Commit Graph

1926 Commits

Author SHA1 Message Date
Ingo Molnar 80b304fd00 * WARN_ON(!spin_is_locked()) always triggers on non-SMP machines.
Swap it for the more canonical lockdep_assert_held() which always
    does the right thing - Guenter Roeck
 
  * Assign the correct value to efi.runtime_version on arm64 so that all
    the runtime services can be invoked - Semen Protsenko
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Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent

Pull EFI fixes from Matt Fleming:

 * WARN_ON(!spin_is_locked()) always triggers on non-SMP machines.
   Swap it for the more canonical lockdep_assert_held() which always
   does the right thing - Guenter Roeck

 * Assign the correct value to efi.runtime_version on arm64 so that all
   the runtime services can be invoked - Semen Protsenko

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-22 10:04:15 +02:00
Jeremiah Mahler 86426851c3 x86/mm: Fix sparse 'tlb_single_page_flush_ceiling' warning and make the variable read-mostly
A sparse warning is generated about
'tlb_single_page_flush_ceiling' not being declared.

  arch/x86/mm/tlb.c:177:15: warning: symbol
  'tlb_single_page_flush_ceiling' was not declared. Should it be static?

Since it isn't used anywhere outside this file, fix the warning
by making it static.

Also, optimize the use of this variable by adding the
__read_mostly directive, as suggested by David Rientjes.

Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1407569913-4035-1-git-send-email-jmmahler@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-10 09:07:18 +02:00
Dave Hansen 7c7f1547b6 x86/mm: Fix RCU splat from new TLB tracepoints
Dave Jones reported seeing a bug from one of my TLB tracepoints:

        http://lkml.kernel.org/r/20140806181801.GA4605@redhat.com

According to Paul McKenney, the right way to fix this is adding
an _rcuidle suffix to the tracepoint.

        http://lkml.kernel.org/r/20140807065055.GA5821@linux.vnet.ibm.com

This patch does just that.

Reported-by: Dave Jones <davej@redhat.com>,
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140807175841.5C92D878@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-08 10:35:00 +02:00
Wang Nan 03d4be6460 memory-hotplug: x86_32: suitable memory should go to ZONE_MOVABLE
This patch introduces zone_for_memory() to arch_add_memory() on x86_32
to ensure new, higher memory added into ZONE_MOVABLE if movable zone has
already setup.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Mel Gorman" <mgorman@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
Wang Nan 9bfc411385 memory-hotplug: x86_64: suitable memory should go to ZONE_MOVABLE
This patch introduces zone_for_memory() to arch_add_memory() on x86_64
to ensure new, higher memory added into ZONE_MOVABLE if movable zone has
already setup.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Mel Gorman" <mgorman@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:21 -07:00
Paul Cassella 9a95f3cf7b mm: describe mmap_sem rules for __lock_page_or_retry() and callers
Add a comment describing the circumstances in which
__lock_page_or_retry() will or will not release the mmap_sem when
returning 0.

Add comments to lock_page_or_retry()'s callers (filemap_fault(),
do_swap_page()) noting the impact on VM_FAULT_RETRY returns.

Add comments on up the call tree, particularly replacing the false "We
return with mmap_sem still held" comments.

Signed-off-by: Paul Cassella <cassella@cray.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:20 -07:00
Linus Torvalds ce47479632 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm changes from Ingo Molnar:
 "The main change in this cycle is the rework of the TLB range flushing
  code, to simplify, fix and consolidate the code.  By Dave Hansen"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Set TLB flush tunable to sane value (33)
  x86/mm: New tunable for single vs full TLB flush
  x86/mm: Add tracepoints for TLB flushes
  x86/mm: Unify remote INVLPG code
  x86/mm: Fix missed global TLB flush stat
  x86/mm: Rip out complicated, out-of-date, buggy TLB flushing
  x86/mm: Clean up the TLB flushing code
  x86/smep: Be more informative when signalling an SMEP fault
2014-08-04 17:15:45 -07:00
Dave Hansen a5102476a2 x86/mm: Set TLB flush tunable to sane value (33)
This has been run through Intel's LKP tests across a wide range
of modern sytems and workloads and it wasn't shown to make a
measurable performance difference positive or negative.

Now that we have some shiny new tracepoints, we can actually
figure out what the heck is going on.

During a kernel compile, 60% of the flush_tlb_mm_range() calls
are for a single page.  It breaks down like this:

 size   percent  percent<=
  V        V        V
GLOBAL:   2.20%   2.20% avg cycles:  2283
     1:  56.92%  59.12% avg cycles:  1276
     2:  13.78%  72.90% avg cycles:  1505
     3:   8.26%  81.16% avg cycles:  1880
     4:   7.41%  88.58% avg cycles:  2447
     5:   1.73%  90.31% avg cycles:  2358
     6:   1.32%  91.63% avg cycles:  2563
     7:   1.14%  92.77% avg cycles:  2862
     8:   0.62%  93.39% avg cycles:  3542
     9:   0.08%  93.47% avg cycles:  3289
    10:   0.43%  93.90% avg cycles:  3570
    11:   0.20%  94.10% avg cycles:  3767
    12:   0.08%  94.18% avg cycles:  3996
    13:   0.03%  94.20% avg cycles:  4077
    14:   0.02%  94.23% avg cycles:  4836
    15:   0.04%  94.26% avg cycles:  5699
    16:   0.06%  94.32% avg cycles:  5041
    17:   0.57%  94.89% avg cycles:  5473
    18:   0.02%  94.91% avg cycles:  5396
    19:   0.03%  94.95% avg cycles:  5296
    20:   0.02%  94.96% avg cycles:  6749
    21:   0.18%  95.14% avg cycles:  6225
    22:   0.01%  95.15% avg cycles:  6393
    23:   0.01%  95.16% avg cycles:  6861
    24:   0.12%  95.28% avg cycles:  6912
    25:   0.05%  95.32% avg cycles:  7190
    26:   0.01%  95.33% avg cycles:  7793
    27:   0.01%  95.34% avg cycles:  7833
    28:   0.01%  95.35% avg cycles:  8253
    29:   0.08%  95.42% avg cycles:  8024
    30:   0.03%  95.45% avg cycles:  9670
    31:   0.01%  95.46% avg cycles:  8949
    32:   0.01%  95.46% avg cycles:  9350
    33:   3.11%  98.57% avg cycles:  8534
    34:   0.02%  98.60% avg cycles: 10977
    35:   0.02%  98.62% avg cycles: 11400

We get in to dimishing returns pretty quickly.  On pre-IvyBridge
CPUs, we used to set the limit at 8 pages, and it was set at 128
on IvyBrige.  That 128 number looks pretty silly considering that
less than 0.5% of the flushes are that large.

The previous code tried to size this number based on the size of
the TLB.  Good idea, but it's error-prone, needs maintenance
(which it didn't get up to now), and probably would not matter in
practice much.

Settting it to 33 means that we cover the mallopt
M_TRIM_THRESHOLD, which is the most universally common size to do
flushes.

That's the short version.  Here's the long one for why I chose 33:

1. These numbers have a constant bias in the timestamps from the
   tracing.  Probably counts for a couple hundred cycles in each of
   these tests, but it should be fairly _even_ across all of them.
   The smallest delta between the tracepoints I have ever seen is
   335 cycles.  This is one reason the cycles/page cost goes down in
   general as the flushes get larger.  The true cost is nearer to
   100 cycles.
2. A full flush is more expensive than a single invlpg, but not
   by much (single percentages).
3. A dtlb miss is 17.1ns (~45 cycles) and a itlb miss is 13.0ns
   (~34 cycles).  At those rates, refilling the 512-entry dTLB takes
   22,000 cycles.
4. 22,000 cycles is approximately the equivalent of doing 85
   invlpg operations.  But, the odds are that the TLB can
   actually be filled up faster than that because TLB misses that
   are close in time also tend to leverage the same caches.
6. ~98% of flushes are <=33 pages.  There are a lot of flushes of
   33 pages, probably because libc's M_TRIM_THRESHOLD is set to
   128k (32 pages)
7. I've found no consistent data to support changing the IvyBridge
   vs. SandyBridge tunable by a factor of 16

I used the performance counters on this hardware (IvyBridge i5-3320M)
to figure out the tlb miss costs:

ocperf.py stat -e dtlb_load_misses.walk_duration,dtlb_load_misses.walk_completed,dtlb_store_misses.walk_duration,dtlb_store_misses.walk_completed,itlb_misses.walk_duration,itlb_misses.walk_completed,itlb.itlb_flush

     7,720,030,970      dtlb_load_misses_walk_duration                                    [57.13%]
       169,856,353      dtlb_load_misses_walk_completed                                    [57.15%]
       708,832,859      dtlb_store_misses_walk_duration                                    [57.17%]
        19,346,823      dtlb_store_misses_walk_completed                                    [57.17%]
     2,779,687,402      itlb_misses_walk_duration                                    [57.15%]
        82,241,148      itlb_misses_walk_completed                                    [57.13%]
           770,717      itlb_itlb_flush                                              [57.11%]

Show that a dtlb miss is 17.1ns (~45 cycles) and a itlb miss is 13.0ns
(~34 cycles).  At those rates, refilling the 512-entry dTLB takes
22,000 cycles.  On a SandyBridge system with more cores and larger
caches, those are dtlb=13.4ns and itlb=9.5ns.

cat perf.stat.txt | perl -pe 's/,//g'
	| awk '/itlb_misses_walk_duration/ { icyc+=$1 }
		/itlb_misses_walk_completed/ { imiss+=$1 }
		/dtlb_.*_walk_duration/ { dcyc+=$1 }
		/dtlb_.*.*completed/ { dmiss+=$1 }
		END {print "itlb cyc/miss: ", icyc/imiss, " dtlb cyc/miss: ", dcyc/dmiss, "   -----    ", icyc,imiss, dcyc,dmiss }

On Westmere CPUs, the counters to use are: itlb_flush,itlb_misses.walk_cycles,itlb_misses.any,dtlb_misses.walk_cycles,dtlb_misses.any

The assumptions that this code went in under:
https://lkml.org/lkml/2012/6/12/119 say that a flush and a refill are
about 100ns.  Being generous, that is over by a factor of 6 on the
refill side, although it is fairly close on the cost of an invlpg.
An increase of a single invlpg operation seems to lengthen the flush
range operation by about 200 cycles.  Here is one example of the data
collected for flushing 10 and 11 pages (full data are below):

    10:   0.43%  93.90% avg cycles:  3570 cycles/page:  357 samples: 4714
    11:   0.20%  94.10% avg cycles:  3767 cycles/page:  342 samples: 2145

How to generate this table:

	echo 10000 > /sys/kernel/debug/tracing/buffer_size_kb
	echo x86-tsc > /sys/kernel/debug/tracing/trace_clock
	echo 'reason != 0' > /sys/kernel/debug/tracing/events/tlb/tlb_flush/filter
	echo 1 > /sys/kernel/debug/tracing/events/tlb/tlb_flush/enable

Pipe the trace output in to this script:

	http://sr71.net/~dave/intel/201402-tlb/trace-time-diff-process.pl.txt

Note that these data were gathered with the invlpg threshold set to
150 pages.  Only data points with >=50 of samples were printed:

Flush    % of     %<=
in       flush    this
pages      es     size
------------------------------------------------------------------------------
    -1:   2.20%   2.20% avg cycles:  2283 cycles/page: xxxx samples: 23960
     1:  56.92%  59.12% avg cycles:  1276 cycles/page: 1276 samples: 620895
     2:  13.78%  72.90% avg cycles:  1505 cycles/page:  752 samples: 150335
     3:   8.26%  81.16% avg cycles:  1880 cycles/page:  626 samples: 90131
     4:   7.41%  88.58% avg cycles:  2447 cycles/page:  611 samples: 80877
     5:   1.73%  90.31% avg cycles:  2358 cycles/page:  471 samples: 18885
     6:   1.32%  91.63% avg cycles:  2563 cycles/page:  427 samples: 14397
     7:   1.14%  92.77% avg cycles:  2862 cycles/page:  408 samples: 12441
     8:   0.62%  93.39% avg cycles:  3542 cycles/page:  442 samples: 6721
     9:   0.08%  93.47% avg cycles:  3289 cycles/page:  365 samples: 917
    10:   0.43%  93.90% avg cycles:  3570 cycles/page:  357 samples: 4714
    11:   0.20%  94.10% avg cycles:  3767 cycles/page:  342 samples: 2145
    12:   0.08%  94.18% avg cycles:  3996 cycles/page:  333 samples: 864
    13:   0.03%  94.20% avg cycles:  4077 cycles/page:  313 samples: 289
    14:   0.02%  94.23% avg cycles:  4836 cycles/page:  345 samples: 236
    15:   0.04%  94.26% avg cycles:  5699 cycles/page:  379 samples: 390
    16:   0.06%  94.32% avg cycles:  5041 cycles/page:  315 samples: 643
    17:   0.57%  94.89% avg cycles:  5473 cycles/page:  321 samples: 6229
    18:   0.02%  94.91% avg cycles:  5396 cycles/page:  299 samples: 224
    19:   0.03%  94.95% avg cycles:  5296 cycles/page:  278 samples: 367
    20:   0.02%  94.96% avg cycles:  6749 cycles/page:  337 samples: 185
    21:   0.18%  95.14% avg cycles:  6225 cycles/page:  296 samples: 1964
    22:   0.01%  95.15% avg cycles:  6393 cycles/page:  290 samples: 83
    23:   0.01%  95.16% avg cycles:  6861 cycles/page:  298 samples: 61
    24:   0.12%  95.28% avg cycles:  6912 cycles/page:  288 samples: 1307
    25:   0.05%  95.32% avg cycles:  7190 cycles/page:  287 samples: 533
    26:   0.01%  95.33% avg cycles:  7793 cycles/page:  299 samples: 94
    27:   0.01%  95.34% avg cycles:  7833 cycles/page:  290 samples: 66
    28:   0.01%  95.35% avg cycles:  8253 cycles/page:  294 samples: 73
    29:   0.08%  95.42% avg cycles:  8024 cycles/page:  276 samples: 846
    30:   0.03%  95.45% avg cycles:  9670 cycles/page:  322 samples: 296
    31:   0.01%  95.46% avg cycles:  8949 cycles/page:  288 samples: 79
    32:   0.01%  95.46% avg cycles:  9350 cycles/page:  292 samples: 60
    33:   3.11%  98.57% avg cycles:  8534 cycles/page:  258 samples: 33936
    34:   0.02%  98.60% avg cycles: 10977 cycles/page:  322 samples: 268
    35:   0.02%  98.62% avg cycles: 11400 cycles/page:  325 samples: 177
    36:   0.01%  98.63% avg cycles: 11504 cycles/page:  319 samples: 161
    37:   0.02%  98.65% avg cycles: 11596 cycles/page:  313 samples: 182
    38:   0.02%  98.66% avg cycles: 11850 cycles/page:  311 samples: 195
    39:   0.01%  98.68% avg cycles: 12158 cycles/page:  311 samples: 128
    40:   0.01%  98.68% avg cycles: 11626 cycles/page:  290 samples: 78
    41:   0.04%  98.73% avg cycles: 11435 cycles/page:  278 samples: 477
    42:   0.01%  98.73% avg cycles: 12571 cycles/page:  299 samples: 74
    43:   0.01%  98.74% avg cycles: 12562 cycles/page:  292 samples: 78
    44:   0.01%  98.75% avg cycles: 12991 cycles/page:  295 samples: 108
    45:   0.01%  98.76% avg cycles: 13169 cycles/page:  292 samples: 78
    46:   0.02%  98.78% avg cycles: 12891 cycles/page:  280 samples: 261
    47:   0.01%  98.79% avg cycles: 13099 cycles/page:  278 samples: 67
    48:   0.01%  98.80% avg cycles: 13851 cycles/page:  288 samples: 77
    49:   0.01%  98.80% avg cycles: 13749 cycles/page:  280 samples: 66
    50:   0.01%  98.81% avg cycles: 13949 cycles/page:  278 samples: 73
    52:   0.00%  98.82% avg cycles: 14243 cycles/page:  273 samples: 52
    54:   0.01%  98.83% avg cycles: 15312 cycles/page:  283 samples: 87
    55:   0.01%  98.84% avg cycles: 15197 cycles/page:  276 samples: 109
    56:   0.02%  98.86% avg cycles: 15234 cycles/page:  272 samples: 208
    57:   0.00%  98.86% avg cycles: 14888 cycles/page:  261 samples: 53
    58:   0.01%  98.87% avg cycles: 15037 cycles/page:  259 samples: 59
    59:   0.01%  98.87% avg cycles: 15752 cycles/page:  266 samples: 63
    62:   0.00%  98.89% avg cycles: 16222 cycles/page:  261 samples: 54
    64:   0.02%  98.91% avg cycles: 17179 cycles/page:  268 samples: 248
    65:   0.12%  99.03% avg cycles: 18762 cycles/page:  288 samples: 1324
    85:   0.00%  99.10% avg cycles: 21649 cycles/page:  254 samples: 50
   127:   0.01%  99.18% avg cycles: 32397 cycles/page:  255 samples: 75
   128:   0.13%  99.31% avg cycles: 31711 cycles/page:  247 samples: 1466
   129:   0.18%  99.49% avg cycles: 33017 cycles/page:  255 samples: 1927
   181:   0.33%  99.84% avg cycles:  2489 cycles/page:   13 samples: 3547
   256:   0.05%  99.91% avg cycles:  2305 cycles/page:    9 samples: 550
   512:   0.03%  99.95% avg cycles:  2133 cycles/page:    4 samples: 304
  1512:   0.01%  99.99% avg cycles:  3038 cycles/page:    2 samples: 65

Here are the tlb counters during a 10-second slice of a kernel compile
for a SandyBridge system.  It's better than IvyBridge, but probably
due to the larger caches since this was one of the 'X' extreme parts.

    10,873,007,282      dtlb_load_misses_walk_duration
       250,711,333      dtlb_load_misses_walk_completed
     1,212,395,865      dtlb_store_misses_walk_duration
        31,615,772      dtlb_store_misses_walk_completed
     5,091,010,274      itlb_misses_walk_duration
       163,193,511      itlb_misses_walk_completed
         1,321,980      itlb_itlb_flush

      10.008045158 seconds time elapsed

# cat perf.stat.1392743721.txt | perl -pe 's/,//g' | awk '/itlb_misses_walk_duration/ { icyc+=$1 } /itlb_misses_walk_completed/ { imiss+=$1 } /dtlb_.*_walk_duration/ { dcyc+=$1 } /dtlb_.*.*completed/ { dmiss+=$1 } END {print "itlb cyc/miss: ", icyc/imiss/3.3, " dtlb cyc/miss: ", dcyc/dmiss/3.3, "   -----    ", icyc,imiss, dcyc,dmiss }'
itlb ns/miss:  9.45338  dtlb ns/miss:  12.9716

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154103.10C1115E@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:51 -07:00
Dave Hansen 2d040a1ce9 x86/mm: New tunable for single vs full TLB flush
Most of the logic here is in the documentation file.  Please take
a look at it.

I know we've come full-circle here back to a tunable, but this
new one is *WAY* simpler.  I challenge anyone to describe in one
sentence how the old one worked.  Here's the way the new one
works:

	If we are flushing more pages than the ceiling, we use
	the full flush, otherwise we use per-page flushes.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154101.12B52CAF@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:51 -07:00
Dave Hansen d17d8f9ded x86/mm: Add tracepoints for TLB flushes
We don't have any good way to figure out what kinds of flushes
are being attempted.  Right now, we can try to use the vm
counters, but those only tell us what we actually did with the
hardware (one-by-one vs full) and don't tell us what was actually
_requested_.

This allows us to select out "interesting" TLB flushes that we
might want to optimize (like the ranged ones) and ignore the ones
that we have very little control over (the ones at context
switch).

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154059.4C96CBA5@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:51 -07:00
Dave Hansen a23421f111 x86/mm: Unify remote INVLPG code
There are currently three paths through the remote flush code:

1. full invalidation
2. single page invalidation using invlpg
3. ranged invalidation using invlpg

This takes 2 and 3 and combines them in to a single path by
making the single-page one just be the start and end be start
plus a single page.  This makes placement of our tracepoint easier.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154058.E0F90408@viggo.jf.intel.com
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:51 -07:00
Dave Hansen 9dfa6dee53 x86/mm: Fix missed global TLB flush stat
If we take the

	if (end == TLB_FLUSH_ALL || vmflag & VM_HUGETLB) {
		local_flush_tlb();
		goto out;
	}

path out of flush_tlb_mm_range(), we will have flushed the tlb,
but not incremented NR_TLB_LOCAL_FLUSH_ALL.  This unifies the
way out of the function so that we always take a single path when
doing a full tlb flush.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154056.FF763B76@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:50 -07:00
Dave Hansen e9f4e0a9fe x86/mm: Rip out complicated, out-of-date, buggy TLB flushing
I think the flush_tlb_mm_range() code that tries to tune the
flush sizes based on the CPU needs to get ripped out for
several reasons:

1. It is obviously buggy.  It uses mm->total_vm to judge the
   task's footprint in the TLB.  It should certainly be using
   some measure of RSS, *NOT* ->total_vm since only resident
   memory can populate the TLB.
2. Haswell, and several other CPUs are missing from the
   intel_tlb_flushall_shift_set() function.  Thus, it has been
   demonstrated to bitrot quickly in practice.
3. It is plain wrong in my vm:
	[    0.037444] Last level iTLB entries: 4KB 0, 2MB 0, 4MB 0
	[    0.037444] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0
	[    0.037444] tlb_flushall_shift: 6
   Which leads to it to never use invlpg.
4. The assumptions about TLB refill costs are wrong:
	http://lkml.kernel.org/r/1337782555-8088-3-git-send-email-alex.shi@intel.com
    (more on this in later patches)
5. I can not reproduce the original data: https://lkml.org/lkml/2012/5/17/59
   I believe the sample times were too short.  Running the
   benchmark in a loop yields times that vary quite a bit.

Note that this leaves us with a static ceiling of 1 page.  This
is a conservative, dumb setting, and will be revised in a later
patch.

This also removes the code which attempts to predict whether we
are flushing data or instructions.  We expect instruction flushes
to be relatively rare and not worth tuning for explicitly.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154055.ABC88E89@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:50 -07:00
Dave Hansen 4995ab9cf5 x86/mm: Clean up the TLB flushing code
The

	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)

line of code is not exactly the easiest to audit, especially when
it ends up at two different indentation levels.  This eliminates
one of the the copy-n-paste versions.  It also gives us a unified
exit point for each path through this function.  We need this in
a minute for our tracepoint.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: http://lkml.kernel.org/r/20140731154054.44F1CDDC@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-07-31 08:48:50 -07:00
Linus Torvalds 3737a12761 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more perf updates from Ingo Molnar:
 "A second round of perf updates:

   - wide reaching kprobes sanitization and robustization, with the hope
     of fixing all 'probe this function crashes the kernel' bugs, by
     Masami Hiramatsu.

   - uprobes updates from Oleg Nesterov: tmpfs support, corner case
     fixes and robustization work.

   - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo
     et al:
        * Add support to accumulate hist periods (Namhyung Kim)
        * various fixes, refactorings and enhancements"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
  perf: Differentiate exec() and non-exec() comm events
  perf: Fix perf_event_comm() vs. exec() assumption
  uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates
  perf/documentation: Add description for conditional branch filter
  perf/x86: Add conditional branch filtering support
  perf/tool: Add conditional branch filter 'cond' to perf record
  perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND'
  uprobes: Teach copy_insn() to support tmpfs
  uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()
  perf/x86: Use common PMU interrupt disabled code
  perf/ARM: Use common PMU interrupt disabled code
  perf: Disable sampled events if no PMU interrupt
  perf: Fix use after free in perf_remove_from_context()
  perf tools: Fix 'make help' message error
  perf record: Fix poll return value propagation
  perf tools: Move elide bool into perf_hpp_fmt struct
  perf tools: Remove elide setup for SORT_MODE__MEMORY mode
  perf tools: Fix "==" into "=" in ui_browser__warning assignment
  perf tools: Allow overriding sysfs and proc finding with env var
  perf tools: Consider header files outside perf directory in tags target
  ...
2014-06-12 19:18:49 -07:00
Jiri Kosina eff50c347f x86/smep: Be more informative when signalling an SMEP fault
If pagefault triggers due to SMEP triggering, it can't be really easily
distinguished from any other oops-causing pagefault, which might lead to quite
some confusion when trying to understand the reason for the oops.

Print an explanatory message in case the fault happened during instruction
fetch for _PAGE_USER page which is present and executable on SMEP-enabled CPUs.

This is consistent with what we are doing for NX already; in addition to
immediately seeing from the oops what might be happening, it can even easily
give a good indication to sysadmins who are carefully monitoring their kernel
logs that someone might be trying to pwn them.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1406102248490.1321@pobox.suse.cz
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-06-11 17:55:30 -07:00
Linus Torvalds a0abcf2e8f Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull x86 cdso updates from Peter Anvin:
 "Vdso cleanups and improvements largely from Andy Lutomirski.  This
  makes the vdso a lot less ''special''"

* 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso, build: Make LE access macros clearer, host-safe
  x86/vdso, build: Fix cross-compilation from big-endian architectures
  x86/vdso, build: When vdso2c fails, unlink the output
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
  x86, mm: Improve _install_special_mapping and fix x86 vdso naming
  mm, fs: Add vm_ops->name as an alternative to arch_vma_name
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
  x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
  x86, vdso: Move the 32-bit vdso special pages after the text
  x86, vdso: Reimplement vdso.so preparation in build-time C
  x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
  x86, vdso: Clean up 32-bit vs 64-bit vdso params
  x86, mm: Ensure correct alignment of the fixmap
2014-06-05 08:05:29 -07:00
Linus Torvalds 2071b3e34f Merge branch 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull x86-64 espfix changes from Peter Anvin:
 "This is the espfix64 code, which fixes the IRET information leak as
  well as the associated functionality problem.  With this code applied,
  16-bit stack segments finally work as intended even on a 64-bit
  kernel.

  Consequently, this patchset also removes the runtime option that we
  added as an interim measure.

  To help the people working on Linux kernels for very small systems,
  this patchset also makes these compile-time configurable features"

* 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86-64, modify_ldt: Make support for 16-bit segments a runtime option"
  x86, espfix: Make it possible to disable 16-bit support
  x86, espfix: Make espfix64 a Kconfig option, fix UML
  x86, espfix: Fix broken header guard
  x86, espfix: Move espfix definitions into a separate header file
  x86-32, espfix: Remove filter for espfix32 due to race
  x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack
2014-06-05 07:46:15 -07:00
Emil Medve af4459d363 arch/x86/mm/numa.c: use for_each_memblock()
Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:05 -07:00
Yinghai Lu 982792c782 x86, mm: probe memory block size for generic x86 64bit
On system with 2TiB ram, current x86_64 have 128M as section size, and
one memory_block only include one section.  So will have 16400 entries
under /sys/devices/system/memory/.

Current code try to use block id to find block pointer in /sys for any
section, and reuse that block pointer.  that finding will take some time
even after commit 7c243c7168 ("mm: speedup in __early_pfn_to_nid")
that will skip the search in that case during booting up.

So solution could be increase block size just like SGI UV system did.
(harded code to 2g).

This patch is trying to probe the block size to make it match mmio remap
size.  for example, Intel Nehalem later system will have memory range [0,
TOML), [4g, TOMH].  If the memory hole is 2g and total is 128g, TOM will
be 2g, and TOM2 will be 130g.

We could use 2g as block size instead of default 128M.  That will reduce
number of entries in /sys/devices/system/memory/

On system 6TiB system will reduce boot time by 35 seconds.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Mel Gorman c46a7c817e x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels
_PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting
faults on x86.  Care is taken such that _PAGE_NUMA is used only in
situations where the VMA flags distinguish between NUMA hinting faults
and prot_none faults.  This decision was x86-specific and conceptually
it is difficult requiring special casing to distinguish between PROTNONE
and NUMA ptes based on context.

Fundamentally, we only need the _PAGE_NUMA bit to tell the difference
between an entry that is really unmapped and a page that is protected
for NUMA hinting faults as if the PTE is not present then a fault will
be trapped.

Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset.
This patch shrinks the maximum possible swap size and uses the bit to
uniquely distinguish between NUMA hinting ptes and swap ptes.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Naoya Horiguchi c177c81e09 hugetlb: restrict hugepage_migration_support() to x86_64
Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:51 -07:00
H. Peter Anvin 03c1b4e8e5 Merge remote-tracking branch 'origin/x86/espfix' into x86/vdso
Merge x86/espfix into x86/vdso, due to changes in the vdso setup code
that otherwise cause conflicts.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-21 17:36:33 -07:00
Andy Lutomirski ac49b9a9f2 x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
This removes the last vestiges of arch_vma_name from x86, replacing it
with vm_ops->name.  Good riddance.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e681cb56096eee5b8b8767093a4f6fb82839f0a4.1400538962.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-20 11:39:31 -07:00
Andy Lutomirski a62c34bd2a x86, mm: Improve _install_special_mapping and fix x86 vdso naming
Using arch_vma_name to give special mappings a name is awkward.  x86
currently implements it by comparing the start address of the vma to
the expected address of the vdso.  This requires tracking the start
address of special mappings and is probably buggy if a special vma
is split or moved.

Improve _install_special_mapping to just name the vma directly.  Use
it to give the x86 vvar area a name, which should make CRIU's life
easier.

As a side effect, the vvar area will show up in core dumps.  This
could be considered weird and is fixable.

[hpa: I say we accept this as-is but be prepared to deal with knocking
 out the vvars from core dumps if this becomes a problem.]

Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/276b39b6b645fb11e345457b503f17b83c2c6fd0.1400538962.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-20 11:38:42 -07:00
Andy Lutomirski f40c330091 x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
This makes the 64-bit and x32 vdsos use the same mechanism as the
32-bit vdso.  Most of the churn is deleting all the old fixmap code.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/8af87023f57f6bb96ec8d17fce3f88018195b49b.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 13:19:01 -07:00
Andy Lutomirski 6f121e548f x86, vdso: Reimplement vdso.so preparation in build-time C
Currently, vdso.so files are prepared and analyzed by a combination
of objcopy, nm, some linker script tricks, and some simple ELF
parsers in the kernel.  Replace all of that with plain C code that
runs at build time.

All five vdso images now generate .c files that are compiled and
linked in to the kernel image.

This should cause only one userspace-visible change: the loaded vDSO
images are stripped more heavily than they used to be.  Everything
outside the loadable segment is dropped.  In particular, this causes
the section table and section name strings to be missing.  This
should be fine: real dynamic loaders don't load or inspect these
tables anyway.  The result is roughly equivalent to eu-strip's
--strip-sections option.

The purpose of this change is to enable the vvar and hpet mappings
to be moved to the page following the vDSO load segment.  Currently,
it is possible for the section table to extend into the page after
the load segment, so, if we map it, it risks overlapping the vvar or
hpet page.  This happens whenever the load segment is just under a
multiple of PAGE_SIZE.

The only real subtlety here is that the old code had a C file with
inline assembler that did 'call VDSO32_vsyscall' and a linker script
that defined 'VDSO32_vsyscall = __kernel_vsyscall'.  This most
likely worked by accident: the linker script entry defines a symbol
associated with an address as opposed to an alias for the real
dynamic symbol __kernel_vsyscall.  That caused ld to relocate the
reference at link time instead of leaving an interposable dynamic
relocation.  Since the VDSO32_vsyscall hack is no longer needed, I
now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
work.  vdso2c will generate an error and abort the build if the
resulting image contains any dynamic relocations, so we won't
silently generate bad vdso images.

(Dynamic relocations are a problem because nothing will even attempt
to relocate the vdso.)

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 13:18:51 -07:00
Andy Lutomirski 73159fdcdb x86, mm: Ensure correct alignment of the fixmap
The early_ioremap code requires that its buffers not span a PMD
boundary.  The logic for ensuring that only works if the fixmap is
aligned, so assert that it's aligned correctly.

To make this work reliably, reserve_top_address needs to be
adjusted.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e59a5f4362661f75dd4841fa74e1f2448045e245.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 13:18:25 -07:00
Roland Dreier c81c8a1eee x86, ioremap: Speed up check for RAM pages
In __ioremap_caller() (the guts of ioremap), we loop over the range of
pfns being remapped and checks each one individually with page_is_ram().
For large ioremaps, this can be very slow.  For example, we have a
device with a 256 GiB PCI BAR, and ioremapping this BAR can take 20+
seconds -- sometimes long enough to trigger the soft lockup detector!

Internally, page_is_ram() calls walk_system_ram_range() on a single
page.  Instead, we can make a single call to walk_system_ram_range()
from __ioremap_caller(), and do our further checks only for any RAM
pages that we find.  For the common case of MMIO, this saves an enormous
amount of work, since the range being ioremapped doesn't intersect
system RAM at all.

With this change, ioremap on our 256 GiB BAR takes less than 1 second.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Link: http://lkml.kernel.org/r/1399054721-1331-1-git-send-email-roland@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-02 11:52:26 -07:00
H. Peter Anvin 3891a04aaf x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack
The IRET instruction, when returning to a 16-bit segment, only
restores the bottom 16 bits of the user space stack pointer.  This
causes some 16-bit software to break, but it also leaks kernel state
to user space.  We have a software workaround for that ("espfix") for
the 32-bit kernel, but it relies on a nonzero stack segment base which
is not available in 64-bit mode.

In checkin:

    b3b42ac2cb x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

we "solved" this by forbidding 16-bit segments on 64-bit kernels, with
the logic that 16-bit support is crippled on 64-bit kernels anyway (no
V86 support), but it turns out that people are doing stuff like
running old Win16 binaries under Wine and expect it to work.

This works around this by creating percpu "ministacks", each of which
is mapped 2^16 times 64K apart.  When we detect that the return SS is
on the LDT, we copy the IRET frame to the ministack and use the
relevant alias to return to userspace.  The ministacks are mapped
readonly, so if IRET faults we promote #GP to #DF which is an IST
vector and thus has its own stack; we then do the fixup in the #DF
handler.

(Making #GP an IST exception would make the msr_safe functions unsafe
in NMI/MC context, and quite possibly have other effects.)

Special thanks to:

- Andy Lutomirski, for the suggestion of using very small stack slots
  and copy (as opposed to map) the IRET frame there, and for the
  suggestion to mark them readonly and let the fault promote to #DF.
- Konrad Wilk for paravirt fixup and testing.
- Borislav Petkov for testing help and useful comments.

Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Lutomriski <amluto@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dirk Hohndel <dirk@hohndel.org>
Cc: Arjan van de Ven <arjan.van.de.ven@intel.com>
Cc: comex <comexk@gmail.com>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org> # consider after upstream merge
2014-04-30 14:14:28 -07:00
Masami Hiramatsu 9326638cbe kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation
Use NOKPROBE_SYMBOL macro for protecting functions
from kprobes instead of __kprobes annotation under
arch/x86.

This applies nokprobe_inline annotation for some cases,
because NOKPROBE_SYMBOL() will inhibit inlining by
referring the symbol address.

This just folds a bunch of previous NOKPROBE_SYMBOL()
cleanup patches for x86 to one patch.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20140417081814.26341.51656.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fernando Luis Vázquez Cao <fernando_b1@lab.ntt.co.jp>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Lebon <jlebon@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-24 10:26:38 +02:00
Shaohua Li b13b1d2d86 x86/mm: In the PTE swapout page reclaim case clear the accessed bit instead of flushing the TLB
We use the accessed bit to age a page at page reclaim time,
and currently we also flush the TLB when doing so.

But in some workloads TLB flush overhead is very heavy. In my
simple multithreaded app with a lot of swap to several pcie
SSDs, removing the tlb flush gives about 20% ~ 30% swapout
speedup.

Fortunately just removing the TLB flush is a valid optimization:
on x86 CPUs, clearing the accessed bit without a TLB flush
doesn't cause data corruption.

It could cause incorrect page aging and the (mistaken) reclaim of
hot pages, but the chance of that should be relatively low.

So as a performance optimization don't flush the TLB when
clearing the accessed bit, it will eventually be flushed by
a context switch or a VM operation anyway. [ In the rare
event of it not getting flushed for a long time the delay
shouldn't really matter because there's no real memory
pressure for swapout to react to. ]

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140408075809.GA1764@kernel.org
[ Rewrote the changelog and the code comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-16 08:57:08 +02:00
David Rientjes d0057ca4c1 arch/x86/mm/kmemcheck/kmemcheck.c: use kstrtoint() instead of sscanf()
Kmemcheck should use the preferred interface for parsing command line
arguments, kstrto*(), rather than sscanf() itself.  Use it
appropriately.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 16:48:52 -07:00
Mark Salter 5b7c73e009 x86: use generic early_ioremap
Move x86 over to the generic early ioremap implementation.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:15 -07:00
Dave Young 6b550f6f20 x86/mm: sparse warning fix for early_memremap
This patch series takes the common bits from the x86 early ioremap
implementation and creates a generic implementation which may be used by
other architectures.  The early ioremap interfaces are intended for
situations where boot code needs to make temporary virtual mappings
before the normal ioremap interfaces are available.  Typically, this
means before paging_init() has run.

This patch (of 6):

There's a lot of sparse warnings for code like below: void *a =
early_memremap(phys_addr, size);

early_memremap intend to map kernel memory with ioremap facility, the
return pointer should be a kernel ram pointer instead of iomem one.

For making the function clearer and supressing sparse warnings this patch
do below two things:
1. cast to (__force void *) for the return value of early_memremap
2. add early_memunmap function and pass (__force void __iomem *) to iounmap

From Boris:
  "Ingo told me yesterday, it makes sense too.  I'd guess we can try it.
   FWIW, all callers of early_memremap use the memory they get remapped
   as normal memory so we should be safe"

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:14 -07:00
Linus Torvalds 467cbd207a Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 old platform removal from Peter Anvin:
 "This patchset removes support for several completely obsolete
  platforms, where the maintainers either have completely vanished or
  acked the removal.  For some of them it is questionable if there even
  exists functional specimens of the hardware"

Geert Uytterhoeven apparently thought this was a April Fool's pull request ;)

* 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, platforms: Remove NUMAQ
  x86, platforms: Remove SGI Visual Workstation
  x86, apic: Remove support for IBM Summit/EXA chipset
  x86, apic: Remove support for ia32-based Unisys ES7000
2014-04-02 13:15:58 -07:00
Linus Torvalds 1694f0bb8f Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm change from Ingo Molnar:
 "A micro-optimization for acpi_numa_slit_init()"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Avoid duplicated pxm_to_node() calls
2014-04-01 09:50:01 -07:00
Linus Torvalds 7cc3afdf43 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 EFI changes from Ingo Molnar:
 "The main changes:

  - Add debug code to the dump EFI pagetable - Borislav Petkov

  - Make 1:1 runtime mapping robust when booting on machines with lots
    of memory - Borislav Petkov

  - Move the EFI facilities bits out of 'x86_efi_facility' and into
    efi.flags which is the standard architecture independent place to
    keep EFI state, by Matt Fleming.

  - Add 'EFI mixed mode' support: this allows 64-bit kernels to be
    booted from 32-bit firmware.  This needs a bootloader that supports
    the 'EFI handover protocol'.  By Matt Fleming"

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86, efi: Abstract x86 efi_early calls
  x86/efi: Restore 'attr' argument to query_variable_info()
  x86/efi: Rip out phys_efi_get_time()
  x86/efi: Preserve segment registers in mixed mode
  x86/boot: Fix non-EFI build
  x86, tools: Fix up compiler warnings
  x86/efi: Re-disable interrupts after calling firmware services
  x86/boot: Don't overwrite cr4 when enabling PAE
  x86/efi: Wire up CONFIG_EFI_MIXED
  x86/efi: Add mixed runtime services support
  x86/efi: Firmware agnostic handover entry points
  x86/efi: Split the boot stub into 32/64 code paths
  x86/efi: Add early thunk code to go from 64-bit to 32-bit
  x86/efi: Build our own EFI services pointer table
  efi: Add separate 32-bit/64-bit definitions
  x86/efi: Delete dead code when checking for non-native
  x86/mm/pageattr: Always dump the right page table in an oops
  x86, tools: Consolidate #ifdef code
  x86/boot: Cleanup header.S by removing some #ifdefs
  efi: Use NULL instead of 0 for pointer
  ...
2014-03-31 12:26:05 -07:00
Linus Torvalds 918d80a136 Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu handling changes from Ingo Molnar:
 "Bigger changes:

   - Intel CPU hardware-enablement: new vector instructions support
     (AVX-512), by Fenghua Yu.

   - Support the clflushopt instruction and use it in appropriate
     places.  clflushopt is similar to clflush but with more relaxed
     ordering, by Ross Zwisler.

   - MSR accessor cleanups, by Borislav Petkov.

   - 'forcepae' boot flag for those who have way too much time to spend
     on way too old Pentium-M systems and want to live way too
     dangerously, by Chris Bainbridge"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpu: Add forcepae parameter for booting PAE kernels on PAE-disabled Pentium M
  Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPEC
  x86, intel: Make MSR_IA32_MISC_ENABLE bit constants systematic
  x86, Intel: Convert to the new bit access MSR accessors
  x86, AMD: Convert to the new bit access MSR accessors
  x86: Add another set of MSR accessor functions
  x86: Use clflushopt in drm_clflush_virt_range
  x86: Use clflushopt in drm_clflush_page
  x86: Use clflushopt in clflush_cache_range
  x86: Add support for the clflushopt instruction
  x86, AVX-512: Enable AVX-512 States Context Switch
  x86, AVX-512: AVX-512 Feature Detection
2014-03-31 12:00:45 -07:00
Borislav Petkov b82ad3d394 x86, pageattr: Correct WBINVD spelling in comment
It is WBINVD, for INValiDate and not "wbindv". Use caps for instruction
names, while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1394633584-5509-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-13 15:32:45 -07:00
Peter Zijlstra d4078e2322 x86, trace: Further robustify CR2 handling vs tracing
Building on commit 0ac09f9f8c ("x86, trace: Fix CR2 corruption when
tracing page faults") this patch addresses another few issues:

 - Now that read_cr2() is lifted into trace_do_page_fault(), we should
   pass the address to trace_page_fault_entries() to avoid it
   re-reading a potentially changed cr2.

 - Put both trace_do_page_fault() and trace_page_fault_entries() under
   CONFIG_TRACING.

 - Mark both fault entry functions {,trace_}do_page_fault() as notrace
   to avoid getting __mcount or other function entry trace callbacks
   before we've observed CR2.

 - Mark __do_page_fault() as noinline to guarantee the function tracer
   does get to see the fault.

Cc: <jolsa@redhat.com>
Cc: <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306145300.GO9987@twins.programming.kicks-ass.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-06 10:58:18 -08:00
Matt Fleming 994448f1af Merge remote-tracking branch 'tip/x86/efi-mixed' into efi-for-mingo
Conflicts:
	arch/x86/kernel/setup.c
	arch/x86/platform/efi/efi.c
	arch/x86/platform/efi/efi_64.c
2014-03-05 18:15:37 +00:00
Matt Fleming 4fd69331ad Merge remote-tracking branch 'tip/x86/urgent' into efi-for-mingo
Conflicts:
	arch/x86/include/asm/efi.h
2014-03-05 17:31:41 +00:00
Jiri Olsa 0ac09f9f8c x86, trace: Fix CR2 corruption when tracing page faults
The trace_do_page_fault function trigger tracepoint
and then handles the actual page fault.

This could lead to error if the tracepoint caused page
fault. The original cr2 value gets lost and the original
page fault handler kills current process with SIGSEGV.

This happens if you record page faults with callchain
data, the user part of it will cause tracepoint handler
to page fault:

  # perf record -g -e exceptions:page_fault_user ls

Fixing this by saving the original cr2 value
and using it after tracepoint handler is done.

v2: Moving the cr2 read before exception_enter, because
    it could trigger tracepoint as well.

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1402211701380.6395@vincent-weaver-1.um.maine.edu
Link: http://lkml.kernel.org/r/20140228160526.GD1133@krava.brq.redhat.com
2014-03-04 16:00:14 -08:00
Matt Fleming 426e34cc4f x86/mm/pageattr: Always dump the right page table in an oops
Now that we have EFI-specific page tables we need to lookup the pgd when
dumping those page tables, rather than assuming that swapper_pgdir is
the current pgdir.

Remove the double underscore prefix, which is usually reserved for
static functions.

Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04 21:23:36 +00:00
Borislav Petkov 42a5477251 x86, pageattr: Export page unmapping interface
We will use it in efi so expose it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04 16:17:17 +00:00
Borislav Petkov ef6bea6ddf x86, ptdump: Add the functionality to dump an arbitrary pagetable
With reusing the ->trampoline_pgd page table for mapping EFI regions in
order to use them after having switched to EFI virtual mode, it is very
useful to be able to dump aforementioned page table in dmesg. This adds
that functionality through the walk_pgd_level() interface which can be
called from somewhere else.

The original functionality of dumping to debugfs remains untouched.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-03-04 16:16:17 +00:00
Ross Zwisler 8b80fd8b45 x86: Use clflushopt in clflush_cache_range
If clflushopt is available on the system, use it instead of clflush in
clflush_cache_range.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Link: http://lkml.kernel.org/r/1393441612-19729-3-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-27 08:26:10 -08:00
H. Peter Anvin b5660ba76b x86, platforms: Remove NUMAQ
The NUMAQ support seems to be unmaintained, remove it.

Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/n/530CFD6C.7040705@zytor.com
2014-02-27 08:07:39 -08:00
H. Peter Anvin 4640c7ee9b x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
If CONFIG_X86_SMAP is disabled, smap_violation() tests for conditions
which are incorrect (as the AC flag doesn't matter), causing spurious
faults.

The dynamic disabling of SMAP (nosmap on the command line) is fine
because it disables X86_FEATURE_SMAP, therefore causing the
static_cpu_has() to return false.

Found by Fengguang Wu's test system.

[ v3: move all predicates into smap_violation() ]
[ v2: use IS_ENABLED() instead of #ifdef ]

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
2014-02-13 08:40:52 -08:00