Commit Graph

63 Commits

Author SHA1 Message Date
chris hyser acc455cffa sparc64: Setup sysfs to mark LDOM sockets, cores and threads correctly
commit 5f4826a362405748bbf73957027b77993e61e1af
Author: chris hyser <chris.hyser@oracle.com>
Date:   Tue Apr 21 10:31:38 2015 -0400

    sparc64: Setup sysfs to mark LDOM sockets, cores and threads correctly

    The current sparc kernel has no representation for sockets though tools
    like lscpu can pull this from sysfs. This patch walks the machine
    description cache and socket hierarchy and marks sockets as well as cores
    and threads such that a representative sysfs is created by
    drivers/base/topology.c.

    Before this patch:
        $ lscpu
        Architecture:          sparc64
        CPU op-mode(s):        32-bit, 64-bit
        Byte Order:            Big Endian
        CPU(s):                1024
        On-line CPU(s) list:   0-1023
        Thread(s) per core:    8
        Core(s) per socket:    1     <--- wrong
        Socket(s):             128   <--- wrong
        NUMA node(s):          4
        NUMA node0 CPU(s):     0-255
        NUMA node1 CPU(s):     256-511
        NUMA node2 CPU(s):     512-767
        NUMA node3 CPU(s):     768-1023

        After this patch:
        $ lscpu
        Architecture:          sparc64
        CPU op-mode(s):        32-bit, 64-bit
        Byte Order:            Big Endian
        CPU(s):                1024
        On-line CPU(s) list:   0-1023
        Thread(s) per core:    8
        Core(s) per socket:    32
        Socket(s):             4
        NUMA node(s):          4
        NUMA node0 CPU(s):     0-255
        NUMA node1 CPU(s):     256-511
        NUMA node2 CPU(s):     512-767
        NUMA node3 CPU(s):     768-1023

    Most of this patch was done by Chris with updates by David.

    Signed-off-by: Chris Hyser <chris.hyser@oracle.com>
    Signed-off-by: David Ahern <david.ahern@oracle.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 15:42:56 -04:00
Dave Kleikamp 94ab599076 sparc64: fatal trap should stop all cpus
"echo c > /proc/sysrq-trigger" does not result in a system crash. There
are two problems. One is that the trap handler ignores the global
variable, panic_on_oops. The other is that smp_send_stop() is a no-op
which leaves the other cpus running normally when one cpu panics.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-01 21:42:57 -08:00
David S. Miller ab5c780913 sparc64: Do irq_{enter,exit}() around generic_smp_call_function*().
Otherwise rcu_irq_{enter,exit}() do not happen and we get dumps like:

====================
[  188.275021] ===============================
[  188.309351] [ INFO: suspicious RCU usage. ]
[  188.343737] 3.18.0-rc3-00068-g20f3963-dirty #54 Not tainted
[  188.394786] -------------------------------
[  188.429170] include/linux/rcupdate.h:883 rcu_read_lock() used
illegally while idle!
[  188.505235]
other info that might help us debug this:

[  188.554230]
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
[  188.637587] RCU used illegally from extended quiescent state!
[  188.690684] 3 locks held by swapper/7/0:
[  188.721932]  #0:  (&x->wait#11){......}, at: [<0000000000495de8>] complete+0x8/0x60
[  188.797994]  #1:  (&p->pi_lock){-.-.-.}, at: [<000000000048510c>] try_to_wake_up+0xc/0x400
[  188.881343]  #2:  (rcu_read_lock){......}, at: [<000000000048a910>] select_task_rq_fair+0x90/0xb40
[  188.973043]stack backtrace:
[  188.993879] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 3.18.0-rc3-00068-g20f3963-dirty #54
[  189.076187] Call Trace:
[  189.089719]  [0000000000499360] lockdep_rcu_suspicious+0xe0/0x100
[  189.147035]  [000000000048a99c] select_task_rq_fair+0x11c/0xb40
[  189.202253]  [00000000004852d8] try_to_wake_up+0x1d8/0x400
[  189.252258]  [000000000048554c] default_wake_function+0xc/0x20
[  189.306435]  [0000000000495554] __wake_up_common+0x34/0x80
[  189.356448]  [00000000004955b4] __wake_up_locked+0x14/0x40
[  189.406456]  [0000000000495e08] complete+0x28/0x60
[  189.448142]  [0000000000636e28] blk_end_sync_rq+0x8/0x20
[  189.496057]  [0000000000639898] __blk_mq_end_request+0x18/0x60
[  189.550249]  [00000000006ee014] scsi_end_request+0x94/0x180
[  189.601286]  [00000000006ee334] scsi_io_completion+0x1d4/0x600
[  189.655463]  [00000000006e51c4] scsi_finish_command+0xc4/0xe0
[  189.708598]  [00000000006ed958] scsi_softirq_done+0x118/0x140
[  189.761735]  [00000000006398ec] __blk_mq_complete_request_remote+0xc/0x20
[  189.827383]  [00000000004c75d0] generic_smp_call_function_single_interrupt+0x150/0x1c0
[  189.906581]  [000000000043e514] smp_call_function_single_client+0x14/0x40
====================

Based almost entirely upon a patch by Paul E. McKenney.

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-07 09:50:48 -08:00
Linus Torvalds dbb885fecc Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull arch atomic cleanups from Ingo Molnar:
 "This is a series kept separate from the main locking tree, which
  cleans up and improves various details in the atomics type handling:

   - Remove the unused atomic_or_long() method

   - Consolidate and compress atomic ops implementations between
     architectures, to reduce linecount and to make it easier to add new
     ops.

   - Rewrite generic atomic support to only require cmpxchg() from an
     architecture - generate all other methods from that"

* 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  locking,arch: Use ACCESS_ONCE() instead of cast to volatile in atomic_read()
  locking, mips: Fix atomics
  locking, sparc64: Fix atomics
  locking,arch: Rewrite generic atomic support
  locking,arch,xtensa: Fold atomic_ops
  locking,arch,sparc: Fold atomic_ops
  locking,arch,sh: Fold atomic_ops
  locking,arch,powerpc: Fold atomic_ops
  locking,arch,parisc: Fold atomic_ops
  locking,arch,mn10300: Fold atomic_ops
  locking,arch,mips: Fold atomic_ops
  locking,arch,metag: Fold atomic_ops
  locking,arch,m68k: Fold atomic_ops
  locking,arch,m32r: Fold atomic_ops
  locking,arch,ia64: Fold atomic_ops
  locking,arch,hexagon: Fold atomic_ops
  locking,arch,cris: Fold atomic_ops
  locking,arch,avr32: Fold atomic_ops
  locking,arch,arm64: Fold atomic_ops
  locking,arch,arm: Fold atomic_ops
  ...
2014-10-13 15:48:00 +02:00
David S. Miller ac55c76814 sparc64: Switch to 4-level page tables.
This has become necessary with chips that support more than 43-bits
of physical addressing.

Based almost entirely upon a patch by Bob Picco.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
2014-10-05 16:53:38 -07:00
Peter Zijlstra 4f3316c2b5 locking,arch,sparc: Fold atomic_ops
Many of the atomic op implementations are the same except for one
instruction; fold the lot into a few CPP macros and reduce LoC.

This also prepares for easy addition of new ops.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140508135852.825281379@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-14 12:48:13 +02:00
David S. Miller 8bccf5b313 sparc64: Fix pcr_ops initialization and usage bugs.
Christopher reports that perf_event_print_debug() can crash in uniprocessor
builds.  The crash is due to pcr_ops being NULL.

This happens because pcr_arch_init() is only invoked by smp_cpus_done() which
only executes in SMP builds.

init_hw_perf_events() is closely intertwined with pcr_ops being setup properly,
therefore:

1) Call pcr_arch_init() early on from init_hw_perf_events(), instead of
   from smp_cpus_done().

2) Do not hook up a PMU type if pcr_ops is NULL after pcr_arch_init().

3) Move init_hw_perf_events to a later initcall so that it we will be
   sure to invoke pcr_arch_init() after all cpus are brought up.

Finally, guard the one naked sequence of pcr_ops dereferences in
__global_pmu_self() with an appropriate NULL check.

Reported-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-11 20:45:12 -07:00
Linus Torvalds c4222e4635 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
Pull sparc fixes from David Miller:
 "Sparc sparse fixes from Sam Ravnborg"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next: (67 commits)
  sparc64: fix sparse warnings in int_64.c
  sparc64: fix sparse warning in ftrace.c
  sparc64: fix sparse warning in kprobes.c
  sparc64: fix sparse warning in kgdb_64.c
  sparc64: fix sparse warnings in compat_audit.c
  sparc64: fix sparse warnings in init_64.c
  sparc64: fix sparse warnings in aes_glue.c
  sparc: fix sparse warnings in smp_32.c + smp_64.c
  sparc64: fix sparse warnings in perf_event.c
  sparc64: fix sparse warnings in kprobes.c
  sparc64: fix sparse warning in tsb.c
  sparc64: clean up compat_sigset_t.seta handling
  sparc64: fix sparse "Should it be static?" warnings in signal32.c
  sparc64: fix sparse warnings in sys_sparc32.c
  sparc64: fix sparse warning in pci.c
  sparc64: fix sparse warnings in smp_64.c
  sparc64: fix sparse warning in prom_64.c
  sparc64: fix sparse warning in btext.c
  sparc64: fix sparse warnings in sys_sparc_64.c + unaligned_64.c
  sparc64: fix sparse warning in process_64.c
  ...

Conflicts:
	arch/sparc/include/asm/pgtable_64.h
2014-06-19 07:50:07 -10:00
Sam Ravnborg 59dec13b27 sparc64: fix sparse warnings in init_64.c
Fix following warnings:
init_64.c:191:10: warning: symbol 'dcpage_flushes' was not declared. Should it be static?
init_64.c:193:10: warning: symbol 'dcpage_flushes_xcall' was not declared. Should it be static?

Add extern declaration to asm/setup.h and drop local declaration in smp_64.h

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-18 19:01:34 -07:00
Sam Ravnborg d309129857 sparc: fix sparse warnings in smp_32.c + smp_64.c
Fix following warnings:
smp_32.c:177:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
smp_64.c:1202:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
smp_64.c:989:6: warning: symbol 'kgdb_roundup_cpus' was not declared. Should it be static?

Add prototype to include/linux/profile.h of setup_profiling_timer
Add missing include to smp_64.c

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-18 19:01:33 -07:00
Sam Ravnborg a0c54a21dd sparc64: fix sparse warnings in smp_64.c
Fix following warnings:
smp_64.c:88:6: warning: symbol 'smp_callin' was not declared. Should it be static?
smp_64.c:133:6: warning: symbol 'cpu_panic' was not declared. Should it be static?
smp_64.c:187:6: warning: symbol 'smp_synchronize_tick_client' was not declared. Should it be static?
smp_64.c:821:18: warning: symbol 'smp_call_function_client' was not declared. Should it be static?
smp_64.c:827:18: warning: symbol 'smp_call_function_single_client' was not declared. Should it be static?
smp_64.c:964:18: warning: symbol 'smp_new_mmu_context_version_client' was not declared. Should it be static?
smp_64.c:1149:6: warning: symbol 'smp_capture' was not declared. Should it be static?
smp_64.c:1171:6: warning: symbol 'smp_release' was not declared. Should it be static?
smp_64.c:1190:18: warning: symbol 'smp_penguin_jailcell' was not declared. Should it be static?
smp_64.c:1410:18: warning: symbol 'smp_receive_signal_client' was not declared. Should it be static?

Add prototypes in kernel.h or asm/smp_64.h as appropriate.
Delete duplicate function kimage_addr_to_ra(), and
adapt parameter to const void * to match the broader use.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-18 19:01:31 -07:00
Kirill Tkhai 49b6c01f4c sparc64: Make itc_sync_lock raw
One more place where we must not be able
to be preempted or to be interrupted in RT.

Always actually disable interrupts during
synchronization cycle.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-02 01:15:16 -04:00
Bjorn Helgaas 070826820d sparc64, sched: Remove unused sparc64_multi_core
Remove sparc64_multi_core because it's not used any more.

It was added by a2f9f6bbb3 ("Fix {mc,smt}_capable()"), and the last uses
were removed by e637d96bf462 ("sched: Remove unused mc_capable() and
smt_capable()").

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20140304210744.16893.75929.stgit@bhelgaas-glaptop.roam.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-03-11 12:05:47 +01:00
Kirill Tkhai ce2521bf7d sparc64: smp_callin: Enable irqs after preemption is disabled
Most of other architectures have below suggested order.
So lets do the same to fit generic idle loop scheme better.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-04 17:55:19 -08:00
Kirill Tkhai 1a36265bf7 sparc64: Add self-IPI support for smp_send_reschedule()
CONFIG_NO_HZ_FULL requires possibility of smp_send_reschedule()
for the calling CPU. Currently, it is used in inc_nr_running()
scheduler primitive only.

Nobody calls smp_send_reschedule() from preemptible context
(furthermore, it looks like it will be save if anybody use it
another way in the future). But anyway I add WARN_ON() here
just to return here if anything changes.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-14 14:56:50 -08:00
Paul Gortmaker 2066aadd53 sparc: delete __cpuinit/__CPUINIT usage from all users
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/sparc uses of the __cpuinit macros from
C files and removes __CPUINIT from assembly files.  Note that even
though arch/sparc/kernel/trampoline_64.S has instances of ".previous"
in it, they are all paired off against explicit ".section" directives,
and not implicitly paired with __CPUINIT (unlike mips and arm were).

[1] https://lkml.org/lkml/2013/5/20/589

Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:52 -04:00
Linus Torvalds 8700c95adb Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
 "This is a pretty large, multi-arch series unifying and generalizing
  the various disjunct pieces of idle routines that architectures have
  historically copied from each other and have grown in random, wildly
  inconsistent and sometimes buggy directions:

   101 files changed, 455 insertions(+), 1328 deletions(-)

  this went through a number of review and test iterations before it was
  committed, it was tested on various architectures, was exposed to
  linux-next for quite some time - nevertheless it might cause problems
  on architectures that don't read the mailing lists and don't regularly
  test linux-next.

  This cat herding excercise was motivated by the -rt kernel, and was
  brought to you by Thomas "the Whip" Gleixner."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  idle: Remove GENERIC_IDLE_LOOP config switch
  um: Use generic idle loop
  ia64: Make sure interrupts enabled when we "safe_halt()"
  sparc: Use generic idle loop
  idle: Remove unused ARCH_HAS_DEFAULT_IDLE
  bfin: Fix typo in arch_cpu_idle()
  xtensa: Use generic idle loop
  x86: Use generic idle loop
  unicore: Use generic idle loop
  tile: Use generic idle loop
  tile: Enter idle with preemption disabled
  sh: Use generic idle loop
  score: Use generic idle loop
  s390: Use generic idle loop
  powerpc: Use generic idle loop
  parisc: Use generic idle loop
  openrisc: Use generic idle loop
  mn10300: Use generic idle loop
  mips: Use generic idle loop
  microblaze: Use generic idle loop
  ...
2013-04-30 07:50:17 -07:00
David S. Miller f36391d279 sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.

So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.

Fix this by using generic infrastructure to synchonize on the
completion of the cross call.

This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().

We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls.  If we're not in such a
region, we flush TLBs synchronously.

1) Get rid of xcall_flush_tlb_pending and per-cpu type
   implementations.

2) Do TLB batch cross calls instead via:

	smp_call_function_many()
		tlb_pending_func()
			__flush_tlb_pending()

3) Batch only in lazy mmu sequences:

	a) Add 'active' member to struct tlb_batch
	b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
	c) Set 'active' in arch_enter_lazy_mmu_mode()
	d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
	e) Check 'active' in tlb_batch_add_one() and do a synchronous
           flush if it's clear.

4) Add infrastructure for synchronous TLB page flushes.

	a) Implement __flush_tlb_page and per-cpu variants, patch
	   as needed.
	b) Likewise for xcall_flush_tlb_page.
	c) Implement smp_flush_tlb_page() to invoke the cross-call.
	d) Wire up global_flush_tlb_page() to the right routine based
           upon CONFIG_SMP

5) It turns out that singleton batches are very common, 2 out of every
   3 batch flushes have only a single entry in them.

   The batch flush waiting is very expensive, both because of the poll
   on sibling cpu completeion, as well as because passing the tlb batch
   pointer to the sibling cpus invokes a shared memory dereference.

   Therefore, in flush_tlb_pending(), if there is only one entry in
   the batch perform a completely asynchronous global_flush_tlb_page()
   instead.

Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-19 17:26:26 -04:00
Sam Ravnborg 87fa05aeb3 sparc: Use generic idle loop
Add generic cpu_idle support

sparc32:
- replace call to cpu_idle() with cpu_startup_entry()
- add arch_cpu_idle()

sparc64:
- smp_callin() now include cpu_startup_entry() call so we can
  skip calling cpu_idle from assembler
- add arch_cpu_idle() and arch_cpu_idle_dead()

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: torvalds@linux-foundation.org
Cc: rusty@rustcorp.com.au
Cc: paulmck@linux.vnet.ibm.com
Cc: peterz@infradead.org
Cc: magnus.damm@gmail.com
Acked-by: David Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20130411193850.GA2330@merkur.ravnborg.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-13 21:36:27 +02:00
Greg Kroah-Hartman 7c9503b838 SPARC: drivers: remove __dev* attributes.
CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-03 15:57:04 -08:00
David S. Miller 916ca14aaf sparc64: Add global PMU register dumping via sysrq.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-16 09:34:01 -07:00
Yong Zhang bc68330095 SPARC: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq()
ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock
protects only the call_function data structure itself, but it's
completely unrelated to cpu_online_mask. The mask to which the IPIs
are sent is calculated before call_function.lock is taken in
smp_call_function_many(), so the locking around set_cpu_online() is
pointless and can be removed.

Delay irq enable to after set_cpu_online().

[ tglx: Massaged changelog ]

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: ralf@linux-mips.org
Cc: sshtylyov@mvista.com
Cc: david.daney@cavium.com
Cc: nikunj@linux.vnet.ibm.com
Cc: paulmck@linux.vnet.ibm.com
Cc: axboe@kernel.dk
Cc: peterz@infradead.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20120529082732.GA4250@zhy
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-06-05 17:27:13 +02:00
Thomas Gleixner f0a2bc7e54 sparc: Use generic idle thread allocation
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20120420124558.055198736@linutronix.de
2012-04-26 12:06:12 +02:00
Thomas Gleixner 8239c25f47 smp: Add task_struct argument to __cpu_up()
Preparatory patch to make the idle thread allocation for secondary
cpus generic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
2012-04-26 12:06:09 +02:00
Justin P. Mattock 42b2aa86c6 treewide: Fix typos in various parts of the kernel, and fix some comments.
The below patch fixes some typos in various parts of the kernel, as well as fixes some comments.
Please let me know if I missed anything, and I will try to get it changed and resent.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-02 14:57:31 +01:00
Paul Gortmaker 066bcaca51 sparc: move symbol exporters to use export.h not module.h
Many of the core sparc kernel files are not modules, but just
including module.h for exporting symbols.  Now these files can
use the lighter footprint export.h for this role.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:53 -04:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
David S. Miller 90d3ac15e5 Merge commit '317f394160e9beb97d19a84c39b7e5eb3d7815a8'
Conflicts:
	arch/sparc/kernel/smp_32.c

With merge conflict help from Daniel Hellstrom.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-20 13:10:22 -07:00
KOSAKI Motohiro fb1fece5da sparc: convert old cpumask API into new one
Adapt new API. Almost change is trivial, most important change are to
remove following like =operator.

 cpumask_t cpu_mask = *mm_cpumask(mm);
 cpus_allowed = current->cpus_allowed;

Because cpumask_var_t is =operator unsafe. These usage might prevent
kernel core improvement.

No functional change.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-16 13:38:07 -07:00
Peter Zijlstra 184748cc50 sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()
For future rework of try_to_wake_up() we'd like to push part of that
function onto the CPU the task is actually going to run on.

In order to do so we need a generic callback from the existing scheduler IPI.

This patch introduces such a generic callback: scheduler_ipi() and
implements it as a NOP.

BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions!

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
2011-04-14 08:52:32 +02:00
David S. Miller c6fee0810d sparc64: Fix build errors with gcc-4.6.0
Most of the warnings emitted (we fail arch/sparc file
builds with -Werror) were legitimate but harmless, however
one case (n2_pcr_write) was a genuine bug.

Based almost entirely upon a patch by Sam Ravnborg.

Reported-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-16 18:19:15 -07:00
David S. Miller b62818e5ff sparc64: Fix NMI startup bug which also breaks perf.
Doing NMI startup as an early initcall doesn't work because we need
to have SMP started up by then.

So we'd only NMI startup one cpu, which causes perf PMU grab to
BUG because the nmi_active count isn't what it's supposed to be.

This also points out that we don't have proper CPU up/down notifiers
for the NMI code which will need to be fixed at some point.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-15 15:04:07 -08:00
David S. Miller 9343af084c Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	lib/Kconfig.debug
2010-04-13 00:28:45 -07:00
David S. Miller 9960e9e894 sparc64: Add function graph tracer support.
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-12 22:37:26 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Grant Likely 6016a363f6 of: unify phandle name in struct device_node
In struct device_node, the phandle is named 'linux_phandle' for PowerPC
and MicroBlaze, and 'node' for SPARC.  There is no good reason for the
difference, it is just an artifact of the code diverging over a couple
of years.  This patch renames both to simply .phandle.

Note: the .node also existed in PowerPC/MicroBlaze, but the only user
seems to be arch/powerpc/platforms/powermac/pfunc_core.c.  It doesn't
look like the assignment between .linux_phandle and .node is
significantly different enough to warrant the separate code paths
unless ibm,phandle properties actually appear in Apple device trees.

I think it is safe to eliminate the old .node property and use
phandle everywhere.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-01-28 14:06:53 -07:00
Tejun Heo a70c691376 sparc64: implement page mapping percpu first chunk allocator
Implement page mapping percpu first chunk allocator as a fallback to
the embedding allocator.  The next patch will make the embedding
allocator check distances between units to determine whether it fits
within the vmalloc area so that this fallback can be used on such
cases.

sparc64 currently has relatively small vmalloc area which makes it
impossible to create any dynamic chunks on certain configurations
leading to percpu allocation failures.  This and the next patch should
allow those configurations to keep working until proper solution is
found.

While at it, mark pcpu_cpu_distance() with __init.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
2009-09-29 09:17:57 +09:00
Tejun Heo bcb2107fdb sparc64: use embedding percpu first chunk allocator
sparc64 currently allocates a large page for each cpu and partially
remap them into vmalloc area much like what lpage first chunk
allocator did.  As a 4M page is used for each cpu, this results in
very large unit size and also adds TLB pressure due to the double
mapping of pages in the first chunk.

This patch converts sparc64 to use the embedding percpu first chunk
allocator which now knows how to handle NUMA configurations.  This
simplifies the code a lot, doesn't incur any extra TLB pressure and
results in better utilization of address space.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
2009-08-14 15:00:53 +09:00
Tejun Heo fb435d5233 percpu: add pcpu_unit_offsets[]
Currently units are mapped sequentially into address space.  This
patch adds pcpu_unit_offsets[] which allows units to be mapped to
arbitrary offsets from the chunk base address.  This is necessary to
allow sparse embedding which might would need to allocate address
ranges and memory areas which aren't aligned to unit size but
allocation atom size (page or large page size).  This also simplifies
things a bit by removing the need to calculate offset from unit
number.

With this change, there's no need for the arch code to know
pcpu_unit_size.  Update pcpu_setup_first_chunk() and first chunk
allocators to return regular 0 or -errno return code instead of unit
size or -errno.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
2009-08-14 15:00:51 +09:00
Tejun Heo fd1e8a1fe2 percpu: introduce pcpu_alloc_info and pcpu_group_info
Till now, non-linear cpu->unit map was expressed using an integer
array which maps each cpu to a unit and used only by lpage allocator.
Although how many units have been placed in a single contiguos area
(group) is known while building unit_map, the information is lost when
the result is recorded into the unit_map array.  For lpage allocator,
as all allocations are done by lpages and whether two adjacent lpages
are in the same group or not is irrelevant, this didn't cause any
problem.  Non-linear cpu->unit mapping will be used for sparse
embedding and this grouping information is necessary for that.

This patch introduces pcpu_alloc_info which contains all the
information necessary for initializing percpu allocator.
pcpu_alloc_info contains array of pcpu_group_info which describes how
units are grouped and mapped to cpus.  pcpu_group_info also has
base_offset field to specify its offset from the chunk's base address.
pcpu_build_alloc_info() initializes this field as if all groups are
allocated back-to-back as is currently done but this will be used to
sparsely place groups.

pcpu_alloc_info is a rather complex data structure which contains a
flexible array which in turn points to nested cpu_map arrays.

* pcpu_alloc_alloc_info() and pcpu_free_alloc_info() are provided to
  help dealing with pcpu_alloc_info.

* pcpu_lpage_build_unit_map() is updated to build pcpu_alloc_info,
  generalized and renamed to pcpu_build_alloc_info().
  @cpu_distance_fn may be NULL indicating that all cpus are of
  LOCAL_DISTANCE.

* pcpul_lpage_dump_cfg() is updated to process pcpu_alloc_info,
  generalized and renamed to pcpu_dump_alloc_info().  It now also
  prints which group each alloc unit belongs to.

* pcpu_setup_first_chunk() now takes pcpu_alloc_info instead of the
  separate parameters.  All first chunk allocators are updated to use
  pcpu_build_alloc_info() to build alloc_info and call
  pcpu_setup_first_chunk() with it.  This has the side effect of
  packing units for sparse possible cpus.  ie. if cpus 0, 2 and 4 are
  possible, they'll be assigned unit 0, 1 and 2 instead of 0, 2 and 4.

* x86 setup_pcpu_lpage() is updated to deal with alloc_info.

* sparc64 setup_per_cpu_areas() is updated to build alloc_info.

Although the changes made by this patch are pretty pervasive, it
doesn't cause any behavior difference other than packing of sparse
cpus.  It mostly changes how information is passed among
initialization functions and makes room for more flexibility.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
2009-08-14 15:00:51 +09:00
Tejun Heo 384be2b18a Merge branch 'percpu-for-linus' into percpu-for-next
Conflicts:
	arch/sparc/kernel/smp_64.c
	arch/x86/kernel/cpu/perf_counter.c
	arch/x86/kernel/setup_percpu.c
	drivers/cpufreq/cpufreq_ondemand.c
	mm/percpu.c

Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-14 14:45:31 +09:00
Tejun Heo 74d46d6b2d percpu, sparc64: fix sparse possible cpu map handling
percpu code has been assuming num_possible_cpus() == nr_cpu_ids which
is incorrect if cpu_possible_map contains holes.  This causes percpu
code to access beyond allocated memories and vmalloc areas.  On a
sparc64 machine with cpus 0 and 2 (u60), this triggers the following
warning or fails boot.

 WARNING: at /devel/tj/os/work/mm/vmalloc.c:106 vmap_page_range_noflush+0x1f0/0x240()
 Modules linked in:
 Call Trace:
  [00000000004b17d0] vmap_page_range_noflush+0x1f0/0x240
  [00000000004b1840] map_vm_area+0x20/0x60
  [00000000004b1950] __vmalloc_area_node+0xd0/0x160
  [0000000000593434] deflate_init+0x14/0xe0
  [0000000000583b94] __crypto_alloc_tfm+0xd4/0x1e0
  [00000000005844f0] crypto_alloc_base+0x50/0xa0
  [000000000058b898] alg_test_comp+0x18/0x80
  [000000000058dad4] alg_test+0x54/0x180
  [000000000058af00] cryptomgr_test+0x40/0x60
  [0000000000473098] kthread+0x58/0x80
  [000000000042b590] kernel_thread+0x30/0x60
  [0000000000472fd0] kthreadd+0xf0/0x160
 ---[ end trace 429b268a213317ba ]---

This patch fixes generic percpu functions and sparc64
setup_per_cpu_areas() so that they handle sparse cpu_possible_map
properly.

Please note that on x86, cpu_possible_map() doesn't contain holes and
thus num_possible_cpus() == nr_cpu_ids and this patch doesn't cause
any behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
2009-08-14 13:20:53 +09:00
Tejun Heo 2f39e637ea percpu: allow non-linear / sparse cpu -> unit mapping
Currently cpu and unit are always identity mapped.  To allow more
efficient large page support on NUMA and lazy allocation for possible
but offline cpus, cpu -> unit mapping needs to be non-linear and/or
sparse.  This can be easily implemented by adding a cpu -> unit
mapping array and using it whenever looking up the matching unit for a
cpu.

The only unusal conversion is in pcpu_chunk_addr_search().  The passed
in address is unit0 based and unit0 might not be in use so it needs to
be converted to address of an in-use unit.  This is easily done by
adding the unit offset for the current processor.

[ Impact: allows non-linear/sparse cpu -> unit mapping, no visible change yet ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
2009-07-04 08:11:00 +09:00
Tejun Heo ce3141a277 percpu: drop pcpu_chunk->page[]
percpu core doesn't need to tack all the allocated pages.  It needs to
know whether certain pages are populated and a way to reverse map
address to page when freeing.  This patch drops pcpu_chunk->page[] and
use populated bitmap and vmalloc_to_page() lookup instead.  Using
vmalloc_to_page() exclusively is also possible but complicates first
chunk handling, inflates cache footprint and prevents non-standard
memory allocation for percpu memory.

pcpu_chunk->page[] was used to track each page's allocation and
allowed asymmetric population which happens during failure path;
however, with single bitmap for all units, this is no longer possible.
Bite the bullet and rewrite (de)populate functions so that things are
done in clearly separated steps such that asymmetric population
doesn't happen.  This makes the (de)population process much more
modular and will also ease implementing non-standard memory usage in
the future (e.g. large pages).

This makes @get_page_fn parameter to pcpu_setup_first_chunk()
unnecessary.  The parameter is dropped and all first chunk helpers are
updated accordingly.  Please note that despite the volume most changes
to first chunk helpers are symbol renames for variables which don't
need to be referenced outside of the helper anymore.

This change reduces memory usage and cache footprint of pcpu_chunk.
Now only #unit_pages bits are necessary per chunk.

[ Impact: reduced memory usage and cache footprint for bookkeeping ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
2009-07-04 08:11:00 +09:00
Tejun Heo 38a6be5254 percpu: simplify pcpu_setup_first_chunk()
Now that all first chunk allocator helpers allocate and map the first
chunk themselves, there's no need to have optional default alloc/map
in pcpu_setup_first_chunk().  Drop @populate_pte_fn and only leave
@dyn_size optional and make all other params mandatory.

This makes it much easier to follow what pcpu_setup_first_chunk() is
doing and what actual differences tweaking each parameter results in.

[ Impact: drop unused code path ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
2009-07-04 08:10:59 +09:00
Stephen Rothwell 6ac5c61082 sparc: replace uses of CPU_MASK_ALL_PTR
CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:

	#define CPU_MASK_ALL (cpumask_t) { { ... } }

Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:

	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)

Which formalizes this practice.  One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).

[Description by Rusty Russell]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-16 04:56:55 -07:00
Hong H. Pham 280ff97494 sparc64: fix and optimize irq distribution
irq_choose_cpu() should compare the affinity mask against cpu_online_map
rather than CPU_MASK_ALL, since irq_select_affinity() sets the interrupt's
affinity mask to cpu_online_map "and" CPU_MASK_ALL (which ends up being
just cpu_online_map).  The mask comparison in irq_choose_cpu() will always
fail since the two masks are not the same.  So the CPU chosen is the first CPU
in the intersection of cpu_online_map and CPU_MASK_ALL, which is always CPU0.
That means all interrupts are reassigned to CPU0...

Distributing interrupts to CPUs in a linearly increasing round robin fashion
is not optimal for the UltraSPARC T1/T2.  Also, the irq_rover in
irq_choose_cpu() causes an interrupt to be assigned to a different
processor each time the interrupt is allocated and released.  This may lead
to an unbalanced distribution over time.

A static mapping of interrupts to processors is done to optimize and balance
interrupt distribution.  For the T1/T2, interrupts are spread to different
cores first, and then to strands within a core.

The following is some benchmarks showing the effects of interrupt
distribution on a T2.  The test was done with iperf using a pair of T5220
boxes, each with a 10GBe NIU (XAUI) connected back to back.

  TCP     | Stock       Linear RR IRQ  Optimized IRQ
  Streams | 2.6.30-rc5  Distribution   Distribution
          | GBits/sec   GBits/sec      GBits/sec
  --------+-----------------------------------------
    1       0.839       0.862          0.868
    8       1.16        4.96           5.88
   16       1.15        6.40           8.04
  100       1.09        7.28           8.68

Signed-off-by: Hong H. Pham <hong.pham@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-16 04:56:28 -07:00
David S. Miller 4fd78a5f1e sparc64: Use new dynamic per-cpu allocator.
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-16 04:56:27 -07:00
David S. Miller 0c243ad81f sparc64: Only allocate per-cpu areas for possible cpus.
This gets us real close to the generic implementation of
setup_per_cpu_areas() except:

1) We store the per-cpu offset into the trap_block[], whereas
   the generic code has it's own static array.

2) We have to initialize the %g5 register to hold the boot cpu's
   per-cpu area offset.

3) The OBP/MDESC cpu info scan is performed at the end.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-16 04:56:25 -07:00
David S. Miller 73fffc037e sparc64: Get rid of real_setup_per_cpu_areas().
Now that we defer the cpu_data() initializations to the end of per-cpu
setup, we can get rid of this local hack we had to setup the per-cpu
areas eary.

This is a necessary step in order to support HAVE_DYNAMIC_PER_CPU_AREA
since the per-cpu setup must run when page structs are available.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-16 04:56:23 -07:00