Use a ring-buffer like multi-version object structure which allows
always having a coherent object; we use this to avoid having to
disable IRQs while reading sched_clock() and avoids a problem when
getting an NMI while changing the cyc2ns data.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 331312 257223
(cold) local_clock: 301773 310296 309889
(warm) sched_clock: 38375 38247 25280
(warm) local_clock: 100371 102713 85268
(warm) rdtsc: 27340 27289 24247
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 372706 301224
(cold) local_clock: 396890 399275 399870
(warm) sched_clock: 38194 38124 25630
(warm) local_clock: 143452 148698 129629
(warm) rdtsc: 27345 27365 24307
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SGI UV tlb shootdown code panics the system with a NULL
pointer deference if 'nobau' is specified on the boot
commandline.
uv_flush_tlb_other() gets called for every flush, whether the
BAU is disabled or not. It should not be keeping the s_enters
statistic while the BAU is disabled.
The panic occurs because during initialization
init_per_cpu_tunables() does not set the bcp->statp pointer if
'nobau' was specified.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@vger.kernel.org> # 3.12.x
Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Consider a kernel crash in a module, simulated the following way:
static int my_init(void)
{
char *map = (void *)0x5;
*map = 3;
return 0;
}
module_init(my_init);
When we turn off FRAME_POINTERs, the very first instruction in
that function causes a BUG. The problem is that we print IP in
the BUG report using %pB (from printk_address). And %pB
decrements the pointer by one to fix printing addresses of
functions with tail calls.
This was added in commit 71f9e59800 ("x86, dumpstack: Use
%pB format specifier for stack trace") to fix the call stack
printouts.
So instead of correct output:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
IP: [<ffffffffa01ac000>] my_init+0x0/0x10 [pb173]
We get:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
IP: [<ffffffffa0152000>] 0xffffffffa0151fff
To fix that, we use %pS only for stack addresses printouts (via
newly added printk_stack_address) and %pB for regs->ip (via
printk_address). I.e. we revert to the old behaviour for all
except call stacks. And since from all those reliable is 1, we
remove that parameter from printk_address.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: joe@perches.com
Cc: jirislaby@gmail.com
Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 8eba18428a.
uv_trace() is not used by anything, nor is uv_trace_nmi_func, nor
uv_trace_func.
That's not how we do instrumentation code in the kernel: we add
tracepoints, printk()s, etc. so that everyone not just those with
magic kernel modules can debug a system.
So remove this unused (and misguied) piece of code.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/n/tip-tumfBffmr4jmnt8Gyxanoblg@git.kernel.org
This patch restores the capability to enter KDB (and KGDB) from
the UV NMI handler. This is needed because the UV system
console is not capable of sending the 'break' signal to the
serial console port. It is also useful when the kernel is hung
in such a way that it isn't responding to normal external I/O,
so sending 'g' to sysreq-trigger does not work either.
Another benefit of the external NMI command is that all the cpus
receive the NMI signal at roughly the same time so they are more
closely aligned timewise.
It utilizes the newly added kgdb_nmicallin function to gain
entry to KGDB/KDB by the master. The slaves still enter via the
standard kgdb_nmicallback function. It also uses the new
'send_ready' pointer to tell KGDB/KDB to signal the slaves when
to proceed into the KGDB slave loop.
It is enabled when the nmi action is set to "kdb" and the kernel
is built with CONFIG_KDB enabled. Note that if kgdb is
connected that interface will be used instead.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20131002151418.089692683@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
GCC warned about:
arch/x86/platform/uv/uv_nmi.c: In function ‘uv_nmi_setup’:
arch/x86/platform/uv/uv_nmi.c:664:2: warning: the address of ‘uv_nmi_cpu_mask’ will always evaluate as ‘true’
The reason is this code:
alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL);
BUG_ON(!uv_nmi_cpu_mask);
which is not the way to check for alloc_cpumask_var() failures - its
return code should be checked instead.
Cc: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/n/tip-2pXRemsjupmvonbpmmnzleo1@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds support for the uvtrace module by providing a
skeleton call to the registered trace function. It also
provides another separate 'NMI' tracer that is triggered by the
system wide 'power nmi' command.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20130923212501.185052551@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If a system has hung and it no longer responds to external
events, this patch adds the capability of doing a standard kdump
and system reboot then triggered by the system NMI command.
It is enabled when the nmi action is changed to "kdump" and the
kernel is built with CONFIG_KEXEC enabled.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20130923212500.660567460@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The standard NMI handler dumps the states of all the cpus. This
includes a full register dump and stack trace. This can be way
more information than what is needed. This patch adds a
"summary" dump that is basically a form of the "ps" command. It
includes the symbolic IP address as well as the command field
and basic process information.
It is enabled when the nmi action is changed to "ips".
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20130923212500.507922930@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current UV NMI handler has not been updated for the changes
in the system NMI handler and the perf operations. The UV NMI
handler reads an MMR in the UV Hub to check to see if the NMI
event was caused by the external 'system NMI' that the operator
can initiate on the System Mgmt Controller.
The problem arises when the perf tools are running, causing
millions of perf events per second on very large CPU count
systems. Previously this was okay because the perf NMI handler
ran at a higher priority on the NMI call chain and if the NMI
was a perf event, it would stop calling other NMI handlers
remaining on the NMI call chain.
Now the system NMI handler calls all the handlers on the NMI
call chain including the UV NMI handler. This causes the UV NMI
handler to read the MMRs at the same millions per second rate.
This can lead to significant performance loss and possible
system failures. It also can cause thousands of 'Dazed and
Confused' messages being sent to the system console. This
effectively makes perf tools unusable on UV systems.
To avoid this excessive overhead when perf tools are running,
this code has been optimized to minimize reading of the MMRs as
much as possible, by moving to the NMI_UNKNOWN notifier chain.
This chain is called only when all the users on the standard
NMI_LOCAL call chain have been called and none of them have
claimed this NMI.
There is an exception where the NMI_LOCAL notifier chain is
used. When the perf tools are in use, it's possible that the UV
NMI was captured by some other NMI handler and then either
ignored or mistakenly processed as a perf event. We set a
per_cpu ('ping') flag for those CPUs that ignored the initial
NMI, and then send them an IPI NMI signal. The NMI_LOCAL
handler on each cpu does not need to read the MMR, but instead
checks the in memory flag indicating it was pinged. There are
two module variables, 'ping_count' indicating how many requested
NMI events occurred, and 'ping_misses' indicating how many stray
NMI events. These most likely are perf events so it shows the
overhead of the perf NMI interrupts and how many MMR reads were avoided.
This patch also minimizes the reads of the MMRs by having the
first cpu entering the NMI handler on each node set a per HUB
in-memory atomic value. (Having a per HUB value avoids sending
lock traffic over NumaLink.) Both types of UV NMIs from the SMI
layer are supported.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20130923212500.353547733@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch moves the UV NMI support from the x2apic file to a
new separate uv_nmi.c file in preparation for the next sequence
of patches. It prevents upcoming bloat of the x2apic file, and
has the added benefit of putting the upcoming /sys/module
parameters under the name 'uv_nmi' instead of 'x2apic_uv_x',
which was obscure.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20130923212500.183295611@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 UV3 support update from Ingo Molnar:
"Support for the SGI Ultraviolet System 3 (UV3) platform - the upcoming
third major iteration and upscaling of the SGI UV supercomputing
platform."
* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, uv, uv3: Trim MMR register definitions after code changes for SGI UV3
x86, uv, uv3: Check current gru hub support for SGI UV3
x86, uv, uv3: Update Time Support for SGI UV3
x86, uv, uv3: Update x2apic Support for SGI UV3
x86, uv, uv3: Update Hub Info for SGI UV3
x86, uv, uv3: Update ACPI Check to include SGI UV3
x86, uv, uv3: Update MMR register definitions for SGI Ultraviolet System 3 (UV3)
Pull x86 cleanup patches from Ingo Molnar:
"Misc smaller cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: ptrace.c only needs export.h and not the full module.h
x86, apb_timer: remove unused variable percpu_timer
um: don't compare a pointer to 0
arch/x86/platform/uv: use ARRAY_SIZE where possible
This patch updates time support for the SGI UV3 hub. Since the UV2
and UV3 time support is identical, "is_uvx_hub" is used instead of
having both "is_uv2_hub" and "is_uv3_hub".
Signed-off-by: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/20130211194508.893907185@gulag1.americas.sgi.com
Acked-by: Russ Anderson <rja@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The flush tlb optimization code has logical issue on UV
platform. It doesn't flush the full range at all, since it
simply ignores its 'end' parameter (and hence also the "all"
indicator) in uv_flush_tlb_others() function.
Cliff's notes:
| I tested the patch on a UV. It has the effect of either
| clearing 1 or all TLBs in a cpu. I added some debugging to
| test for the cases when clearing all TLBs is overkill, and in
| practice it happens very seldom.
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Tested-by: Cliff Wickman <cpw@sgi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86/mm changes from Peter Anvin:
"The big change here is the patchset by Alex Shi to use INVLPG to flush
only the affected pages when we only need to flush a small page range.
It also removes the special INVALIDATE_TLB_VECTOR interrupts (32
vectors!) and replace it with an ordinary IPI function call."
Fix up trivial conflicts in arch/x86/include/asm/apic.h (added code next
to changed line)
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tlb: Fix build warning and crash when building for !SMP
x86/tlb: do flush_tlb_kernel_range by 'invlpg'
x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR
x86/tlb: enable tlb flush range support for x86
mm/mmu_gather: enable tlb flush range in generic mmu_gather
x86/tlb: add tlb_flushall_shift knob into debugfs
x86/tlb: add tlb_flushall_shift for specific CPU
x86/tlb: fall back to flush all when meet a THP large page
x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range
x86/tlb_info: get last level TLB entry number of CPU
x86: Add read_mostly declaration/definition to variables from smp.h
x86: Define early read-mostly per-cpu macros
Pull x86/uv changes from Ingo Molnar:
"UV2 BAU productization fixes.
The BAU (Broadcast Assist Unit) is SGI's fancy out of line way on UV
hardware to do TLB flushes, instead of the normal APIC IPI methods.
The commits here fix / work around hangs in their latest hardware
iteration (UV2).
My understanding is that the main purpose of the out of line
signalling channel is to improve scalability: the UV APIC hardware
glue does not handle broadcasting to many CPUs very well, and this
matters most for TLB shootdowns.
[ I don't agree with all aspects of the current approach: in hindsight
it would have been better to link the BAU at the IPI/APIC driver
level instead of the TLB shootdown level, where TLB flushes are
really just one of the uses of broadcast SMP messages. Doing that
would improve scalability in some other ways and it would also
remove a few uglies from the TLB path. It would also be nice to
push more is_uv_system() tests into proper x86_init or x86_platform
callbacks. Cliff? ]"
* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/uv: Work around UV2 BAU hangs
x86/uv: Implement UV BAU runtime enable and disable control via /proc/sgi_uv/
x86/uv: Fix the UV BAU destination timeout period
Pull x86 platform changes from Ingo Molnar:
"This tree mostly involves various APIC driver cleanups/robustization,
and vSMP motivated platform callback improvements/cleanups"
Fix up trivial conflict due to printk cleanup right next to return value
change.
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
Revert "x86/early_printk: Replace obsolete simple_strtoul() usage with kstrtoint()"
x86/apic/x2apic: Use multiple cluster members for the irq destination only with the explicit affinity
x86/apic/x2apic: Limit the vector reservation to the user specified mask
x86/apic: Optimize cpu traversal in __assign_irq_vector() using domain membership
x86/vsmp: Fix vector_allocation_domain's return value
irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up irq_set_affinity() for UP
x86/vsmp: Fix linker error when CONFIG_PROC_FS is not set
x86/apic/es7000: Make apicid of a cluster (not CPU) from a cpumask
x86/apic/es7000+summit: Always make valid apicid from a cpumask
x86/apic/es7000+summit: Fix compile warning in cpu_mask_to_apicid()
x86/apic: Fix ugly casting and branching in cpu_mask_to_apicid_and()
x86/apic: Eliminate cpu_mask_to_apicid() operation
x86/x2apic/cluster: Vector_allocation_domain() should return a value
x86/apic/irq_remap: Silence a bogus pr_err()
x86/vsmp: Ignore IOAPIC IRQ affinity if possible
x86/apic: Make cpu_mask_to_apicid() operations check cpu_online_mask
x86/apic: Make cpu_mask_to_apicid() operations return error code
x86/apic: Avoid useless scanning thru a cpumask in assign_irq_vector()
x86/apic: Try to spread IRQ vectors to different priority levels
x86/apic: Factor out default vector_allocation_domain() operation
...
x86 has no flush_tlb_range support in instruction level. Currently the
flush_tlb_range just implemented by flushing all page table. That is not
the best solution for all scenarios. In fact, if we just use 'invlpg' to
flush few lines from TLB, we can get the performance gain from later
remain TLB lines accessing.
But the 'invlpg' instruction costs much of time. Its execution time can
compete with cr3 rewriting, and even a bit more on SNB CPU.
So, on a 512 4KB TLB entries CPU, the balance points is at:
(512 - X) * 100ns(assumed TLB refill cost) =
X(TLB flush entries) * 100ns(assumed invlpg cost)
Here, X is 256, that is 1/2 of 512 entries.
But with the mysterious CPU pre-fetcher and page miss handler Unit, the
assumed TLB refill cost is far lower then 100ns in sequential access. And
2 HT siblings in one core makes the memory access more faster if they are
accessing the same memory. So, in the patch, I just do the change when
the target entries is less than 1/16 of whole active tlb entries.
Actually, I have no data support for the percentage '1/16', so any
suggestions are welcomed.
As to hugetlb, guess due to smaller page table, and smaller active TLB
entries, I didn't see benefit via my benchmark, so no optimizing now.
My micro benchmark show in ideal scenarios, the performance improves 70
percent in reading. And in worst scenario, the reading/writing
performance is similar with unpatched 3.4-rc4 kernel.
Here is the reading data on my 2P * 4cores *HT NHM EP machine, with THP
'always':
multi thread testing, '-t' paramter is thread number:
with patch unpatched 3.4-rc4
./mprotect -t 1 14ns 24ns
./mprotect -t 2 13ns 22ns
./mprotect -t 4 12ns 19ns
./mprotect -t 8 14ns 16ns
./mprotect -t 16 28ns 26ns
./mprotect -t 32 54ns 51ns
./mprotect -t 128 200ns 199ns
Single process with sequencial flushing and memory accessing:
with patch unpatched 3.4-rc4
./mprotect 7ns 11ns
./mprotect -p 4096 -l 8 -n 10240
21ns 21ns
[ hpa: http://lkml.kernel.org/r/1B4B44D9196EFF41AE41FDA404FC0A100BFF94@SHSMSX101.ccr.corp.intel.com
has additional performance numbers. ]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1340845344-27557-3-git-send-email-alex.shi@intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
On SGI's UV2 the BAU (Broadcast Assist Unit) driver can hang
under a heavy load. To cure this:
- Disable the UV2 extended status mode (see UV2_EXT_SHFT), as
this mode changes BAU behavior in more ways then just delivering
an extra bit of status. Revert status to just two meaningful bits,
like UV1.
- Use no IPI-style resets on UV2. Just give up the request for
whatever the reason it failed and let it be accomplished with
the legacy IPI method.
- Use no alternate sending descriptor (the former UV2 workaround
bcp->using_desc and handle_uv2_busy() stuff). Just disable the
use of the BAU for a period of time in favor of the legacy IPI
method when the h/w bug leaves a descriptor busy.
-- new tunable: giveup_limit determines the threshold at which a hub is
so plugged that it should do all requests with the legacy IPI method for a
period of time
-- generalize disable_for_congestion() (renamed disable_for_period()) for
use whenever a hub should avoid using the BAU for a period of time
Also:
- Fix find_another_by_swack(), which is part of the UV2 bug workaround
- Correct and clarify the statistics (new stats s_overipilimit, s_giveuplimit,
s_enters, s_ipifordisabled, s_plugged, s_congested)
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131459.GC31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch enables the BAU to be turned on or off dynamically.
echo "on" > /proc/sgi_uv/ptc_statistics
echo "off" > /proc/sgi_uv/ptc_statistics
The system may be booted with or without the nobau option.
Whether the system currently has the BAU off can be seen in
the /proc file -- normally with the baustats script.
Each cpu will have a 1 in the bauoff field if the BAU was turned
off, so baustats will give a count of cpus that have it off.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131330.GB31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Correct the calculation of a destination timeout period, which
is used to distinguish between a destination timeout and the
situation where all the target software ack resources are full
and a request is returned immediately.
The problem is that integer arithmetic was overflowing, yielding
a very large result.
Without this fix destination timeouts are identified as resource
'plugged' events and an ipi method of resource releasing is
unnecessarily employed.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131212.GA31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since there are only two locations where cpu_mask_to_apicid() is
called from, remove the operation and use only
cpu_mask_to_apicid_and() instead.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Suggested-and-acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614074935.GE3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SGI Altix UV2 BAU (Broadcast Assist Unit) as used for
tlb-shootdown (selective broadcast mode) always uses UV2
broadcast descriptor format. There is no need to clear the
'legacy' (UV1) mode, because the hardware always uses UV2 mode
for selective broadcast.
But the BIOS uses general broadcast and legacy mode, and the
hardware pays attention to the legacy mode bit for general
broadcast. So the kernel must not clear that mode bit.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/E1SccoO-0002Lh-Cb@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Current cpu_mask_to_apicid() and cpu_mask_to_apicid_and()
implementations have few shortcomings:
1. A value returned by cpu_mask_to_apicid() is written to
hardware registers unconditionally. Should BAD_APICID get ever
returned it will be written to a hardware too. But the value of
BAD_APICID is not universal across all hardware in all modes and
might cause unexpected results, i.e. interrupts might get routed
to CPUs that are not configured to receive it.
2. Because the value of BAD_APICID is not universal it is
counter- intuitive to return it for a hardware where it does not
make sense (i.e. x2apic).
3. cpu_mask_to_apicid_and() operation is thought as an
complement to cpu_mask_to_apicid() that only applies a AND mask
on top of a cpumask being passed. Yet, as consequence of 18374d8
commit the two operations are inconsistent in that of:
cpu_mask_to_apicid() should not get a offline CPU with the cpumask
cpu_mask_to_apicid_and() should not fail and return BAD_APICID
These limitations are impossible to realize just from looking at
the operations prototypes.
Most of these shortcomings are resolved by returning a error
code instead of BAD_APICID. As the result, faults are reported
back early rather than possibilities to cause a unexpected
behaviour exist (in case of [1]).
The only exception is setup_timer_IRQ0_pin() routine. Although
obviously controversial to this fix, its existing behaviour is
preserved to not break the fragile check_timer() and would
better addressed in a separate fix.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120607131559.GF4759@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The interrupt chip irq_set_affinity() functions copy the affinity mask
to irq_data->affinity but return 0, i.e. IRQ_SET_MASK_OK.
IRQ_SET_MASK_OK causes the core code to do another redundant copy.
Return IRQ_SET_MASK_OK_NOCOPY to avoid this.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Cliff Wickman <cpw@sgi.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Keping Chen <chenkeping@huawei.com>
Link: http://lkml.kernel.org/r/1333120296-13563-4-git-send-email-jiang.liu@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Lower the rating of the UV rtc clocksource to just below that of
the tsc, to improve performance.
Reading the tsc clocksource has lower latency than reading the
rtc, so favor it in situations where it is synchronized and
stable. When the tsc is unsynchronized, the rtc needs to be the
chosen clocksource.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Jack Steiner <steiner@sgi.com>
Link: http://lkml.kernel.org/r/20120217141641.GA28063@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Initialize two spinlocks in tlb_uv.c and also properly define/initialize
the uv_irq_lock.
The lack of explicit initialization seems to be functionally
harmless, but it is diagnosed when these are turned on:
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_LOCKDEP=y
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Link: http://lkml.kernel.org/r/E1RnXd1-0003wU-PM@eag09.americas.sgi.com
[ Added the uv_irq_lock initialization fix by Dimitri Sivanich ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds separate accounting of UV2 message "strong
nack's" in the BAU statistics.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212238.GF5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch moves the ack of the BAU interrupt to the beginning
of the interrupt handler so that there is less possibility of a
lost interrupt and slower response to a shootdown message.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212146.GE5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch removes an unnecessary test for a
no-destination-resources-available condition that looks like a
destination timeout in UV1, but is separately distinguishable in
UV2.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212050.GD5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch implements a workaround for a UV2 hardware bug.
The bug is a non-atomic update of a memory-mapped register. When
hardware message delivery and software message acknowledge occur
simultaneously the pending message acknowledge for the arriving
message may be lost. This causes the sender's message status to
stay busy.
Part of the workaround is to not acknowledge a completed message
until it is verified that no other message is actually using the
resource that is mistakenly recorded in the completed message.
Part of the workaround is to test for long elapsed time in such
a busy condition, then handle it by using a spare sending
descriptor. The stay-busy condition is eventually timed out by
hardware, and then the original sending descriptor can be
re-used. Most of that logic change is in keeping track of the
current descriptor and the state of the spares.
The occurrences of the workaround are added to the BAU
statistics.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211947.GC5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the call to enable_timeouts() forward so that
BAU_MISC_CONTROL is initialized before using it in
calculate_destination_timeout().
Fix the calculation of a BAU destination timeout
for UV2 (in calculate_destination_timeout()).
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211848.GB5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Update the use of the Broadcast Assist Unit on SGI Altix UV2 to
the use of native UV2 mode on new hardware (not the legacy mode).
UV2 native mode has a different format for a broadcast message.
We also need quick differentiaton between UV1 and UV2.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211750.GA5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The sysdev.h file should not be needed by any in-kernel code, so remove
the .h file from these random files that seem to still want to include
it.
The sysdev code will be going away soon, so this include needs to be
removed no matter what.
Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "Venkatesh Pallipadi
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
These files were implicitly getting EXPORT_SYMBOL via device.h
which was including module.h, but that will be fixed up shortly.
By fixing these now, we can avoid seeing things like:
arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’
[ with input from Randy Dunlap <rdunlap@xenotime.net> and also
from Stephen Rothwell <sfr@canb.auug.org.au> ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This is a workaround for a UV2 hub bug that affects the format of system
global addresses.
The GRU API for UV2 was inadvertently broken by a hardware change. The
format of the physical address used for TLB dropins and for addresses used
with instructions running in unmapped mode has changed. This change was
not documented and became apparent only when diags failed running on
system simulators.
For UV1, TLB and GRU instruction physical addresses are identical to
socket physical addresses (although high NASID bits must be OR'ed into the
address).
For UV2, socket physical addresses need to be converted. The NODE portion
of the physical address needs to be shifted so that the low bit is in bit
39 or bit 40, depending on an MMR value.
It is not yet clear if this bug will be fixed in a silicon respin. If it
is fixed, the hub revision will be incremented & the workaround disabled.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix a memory leak in init_per_cpu() when the topology check
fails.
The leak should never occur on deployed systems. It would only occur
in an unexpected topology that would make the BAU unuseable as a result.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.981533045@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove the large stack-resident cpumask_t from
reset_with_ipi()'s stack by allocating one per uvhub.
Due to the limited size of the stack the potentially huge cpumask_t may
cause stack overrun. We haven't seen it happen yet, but we need to make it
a practice not to push such structures onto the stack.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20110621122242.832589130@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename 'bau_targ_hubmask' to 'pnmask' for clarity.
The BAU distribution bit mask is indexed by pnode number, not hub or
blade number. This important fact is not clear while the mask is
called a 'hubmask'.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.630995969@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix reset_with_ipi() to look up a cpu for a blade based on the
distribution map being indexed by the potentially sparsely
numbered pnode.
This patch is critical to tlb shootdown on a partitioned UV
system, or one with nonconsecutive blade numbers.
The distribution map bits represent pnodes relative to the partition base
pnode. Previous to this patch it had been assuming bits based on 0-based,
consecutive blade ids.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.497700003@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix for the topology in which there is a socket 1 on a blade
with no socket 0.
Only call make_per_cpu_thp() for present sockets.
We have only seen this fail for internal configurations.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.363757364@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a call by tunables_write() to smp_processor_id() within a
preemptable region.
Call get_cpu()/put_cpu() around the region where the returned
cpu number is actually used, which makes it non-preemptable.
A DEBUG_PREEMPT warning is prevented.
UV does not support cpu hotplug yet, but this is a step toward
that ability as well.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.086384966@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
SGI UV's uv_tlb.c driver has become rather hard to read, with overly large
functions, non-standard coding style and (way) too long variable, constant
and function names and non-obvious code flow sequences.
This patch improves the readability and maintainability of the driver
significantly, by doing the following strict code cleanups with no side
effects:
- Split long functions into shorter logical functions.
- Shortened some variable and structure member names.
- Added special functions for reads and writes of MMR regs with
very long names.
- Added the 'tunables' table to shortened tunables_write().
- Added the 'stat_description' table to shorten uv_ptc_proc_write().
- Pass fewer 'stat' arguments where it can be derived from the 'bcp'
argument.
- Function definitions consistent on one line, and inline in few (short) cases.
- Moved some small structures and an atomic inline function to the header file.
- Moved some local variables to the blocks where they are used.
- Updated the copyright date.
- Shortened uv_write_global_mmr64() etc. using some aliasing; no
line breaks. Renamed many uv_.. functions that are not exported.
- Aligned structure fields.
[ note that not all structures are aligned the same way though; I'd like
to keep the extensive commenting in some of them. ]
- Shortened some long structure names.
- Standard pass/fail exit from init_per_cpu()
- Vertical alignment for mass initializations.
- More separation between blocks of code.
Tested on a 16-processor Altix UV.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: penberg@kernel.org
Link: http://lkml.kernel.org/r/E1QOw12-0004MN-Lp@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds support for a new version of the SGI UV hub
chip. The hub chip is the node controller that connects multiple
blades into a larger coherent SSI.
For the most part, UV2 is compatible with UV1. The majority of
the changes are in the addresses of MMRs and in a few cases, the
contents of MMRs. These changes are the result in changes in the
system topology such as node configuration, processor types,
maximum nodes, physical address sizes, etc.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Link: http://lkml.kernel.org/r/20110511175028.GA18006@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clocksource: convert mips to generic i8253 clocksource
clocksource: convert x86 to generic i8253 clocksource
clocksource: convert footbridge to generic i8253 clocksource
clocksource: add common i8253 PIT clocksource
blackfin: convert to clocksource_register_hz
mips: convert to clocksource_register_hz/khz
sparc: convert to clocksource_register_hz/khz
alpha: convert to clocksource_register_hz
microblaze: convert to clocksource_register_hz/khz
ia64: convert to clocksource_register_hz/khz
x86: Convert remaining x86 clocksources to clocksource_register_hz/khz
Make clocksource name const
Peter Zijlstra