| 62b94a08da1bae9d187d49dfcd6665af393750f8 |
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20-Nov-2013 |
Peter Zijlstra <peterz@infradead.org> |
sched/preempt: Take away preempt_enable_no_resched() from modules
Discourage drivers/modules to be creative with preemption.
Sadly all is implemented in macros and inline so if they want to do
evil they still can, but at least try and discourage some.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: rui.zhang@intel.com
Cc: jacob.jun.pan@linux.intel.com
Cc: Mike Galbraith <bitbucket@online.de>
Cc: hpa@zytor.com
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: lenb@kernel.org
Cc: rjw@rjwysocki.net
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-fn7h6vu8wtgxk0ih402qcijx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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| bdb43806589096ac4272fe1307e789846ac08d7c |
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10-Sep-2013 |
Peter Zijlstra <peterz@infradead.org> |
sched: Extract the basic add/sub preempt_count modifiers
Rewrite the preempt_count macros in order to extract the 3 basic
preempt_count value modifiers:
__preempt_count_add()
__preempt_count_sub()
and the new:
__preempt_count_dec_and_test()
And since we're at it anyway, replace the unconventional
$op_preempt_count names with the more conventional preempt_count_$op.
Since these basic operators are equivalent to the previous _notrace()
variants, do away with the _notrace() versions.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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| f29c50419c8d1998edd759f1990c4243a248f469 |
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19-May-2011 |
Steven Rostedt <srostedt@redhat.com> |
maccess,probe_kernel: Make write/read src const void *
The functions probe_kernel_write() and probe_kernel_read() do not modify
the src pointer. Allow const pointers to be passed in without the need
of a typecast.
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1305824936.1465.4.camel@gandalf.stny.rr.com
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| 6144a85a0e018c19bc4b24f7eb6c1f3f7431813d |
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07-Jan-2010 |
Jason Wessel <jason.wessel@windriver.com> |
maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write)
Some archs such as blackfin, would like to have an arch specific
probe_kernel_read() and probe_kernel_write() implementation which can
fall back to the generic implementation if no special operations are
needed.
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
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| f180053694b43d5714bf56cb95499a3c32ff155c |
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02-Mar-2009 |
Ingo Molnar <mingo@elte.hu> |
x86, mm: dont use non-temporal stores in pagecache accesses
Impact: standardize IO on cached ops
On modern CPUs it is almost always a bad idea to use non-temporal stores,
as the regression in this commit has shown it:
30d697f: x86: fix performance regression in write() syscall
The kernel simply has no good information about whether using non-temporal
stores is a good idea or not - and trying to add heuristics only increases
complexity and inserts fragility.
The regression on cached write()s took very long to be found - over two
years. So dont take any chances and let the hardware decide how it makes
use of its caches.
The only exception is drivers/gpu/drm/i915/i915_gem.c: there were we are
absolutely sure that another entity (the GPU) will pick up the dirty
data immediately and that the CPU will not touch that data before the
GPU will.
Also, keep the _nocache() primitives to make it easier for people to
experiment with these details. There may be more clear-cut cases where
non-cached copies can be used, outside of filemap.c.
Cc: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| 3255aa2eb636a508fc82a73fabbb8aaf2ff23c0f |
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25-Feb-2009 |
Ingo Molnar <mingo@elte.hu> |
x86, mm: pass in 'total' to __copy_from_user_*nocache()
Impact: cleanup, enable future change
Add a 'total bytes copied' parameter to __copy_from_user_*nocache(),
and update all the callsites.
The parameter is not used yet - architecture code can use it to
more intelligently decide whether the copy should be cached or
non-temporal.
Cc: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| fb71e45338453698bd7460f7e8f171ea0304d218 |
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16-Sep-2008 |
Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> |
uaccess: fix parameters inversion for __copy_from_user_inatomic()
The following patch changes to use __copy_from_user_inatomic(),
but the passing parameters incorrect:
x86: some lock annotations for user copy paths, v3
This fixes the netfilter crash reported by Steven Noonan.
Reported-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Tested-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| 1d18ef489509314506328b9e464dd47c24c1d68f |
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11-Sep-2008 |
Ingo Molnar <mingo@elte.hu> |
x86: some lock annotations for user copy paths, v3
- add annotation back to clear_user()
- change probe_kernel_address() to _inatomic*() method
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| c33fa9f5609e918824446ef9a75319d4a802f1f4 |
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17-Apr-2008 |
Ingo Molnar <mingo@elte.hu> |
uaccess: add probe_kernel_write()
add probe_kernel_read() and probe_kernel_write().
Uninlined and restricted to kernel range memory only, as suggested
by Linus.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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| 20aa7b21b1cbd1aa3fbf5fc14da5f7484a61a824 |
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07-Dec-2006 |
Andrew Morton <akpm@osdl.org> |
[PATCH] probe_kernel_address() needs to do set_fs()
probe_kernel_address() purports to be generic, only it forgot to select
KERNEL_DS, so it presently won't work right on all architectures.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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| a866374aecc90c7d90619727ccd851ac096b2fc7 |
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07-Dec-2006 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
[PATCH] mm: pagefault_{disable,enable}()
Introduce pagefault_{disable,enable}() and use these where previously we did
manual preempt increments/decrements to make the pagefault handler do the
atomic thing.
Currently they still rely on the increased preempt count, but do not rely on
the disabled preemption, this might go away in the future.
(NOTE: the extra barrier() in pagefault_disable might fix some holes on
machines which have too many registers for their own good)
[heiko.carstens@de.ibm.com: s390 fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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| 2fff0a48416af891dce38fd425246e337831e0bb |
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07-Dec-2006 |
Andi Kleen <ak@suse.de> |
[PATCH] Generic: Move __user cast into probe_kernel_address
Caller of probe_kernel_address shouldn't need to know that
pka is internally implemented with __get_user. So move the
__user cast into pka.
Signed-off-by: Andi Kleen <ak@suse.de>
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| 1b79e5513d52e8533a08af35a3595dad80c74d1f |
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27-Sep-2006 |
Andrew Morton <akpm@osdl.org> |
[PATCH] add probe_kernel_address()
Add a version of __get_user() which is safe to call inside mmap_sem.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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| c22ce143d15eb288543fe9873e1c5ac1c01b69a1 |
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23-Jun-2006 |
Hiro Yoshioka <hyoshiok@miraclelinux.com> |
[PATCH] x86: cache pollution aware __copy_from_user_ll()
Use the x86 cache-bypassing copy instructions for copy_from_user().
Some performance data are
Total of GLOBAL_POWER_EVENTS (CPU cycle samples)
2.6.12.4.orig 1921587
2.6.12.4.nt 1599424
1599424/1921587=83.23% (16.77% reduction)
BSQ_CACHE_REFERENCE (L3 cache miss)
2.6.12.4.orig 57427
2.6.12.4.nt 20858
20858/57427=36.32% (63.7% reduction)
L3 cache miss reduction of __copy_from_user_ll
samples %
37408 65.1412 vmlinux __copy_from_user_ll
23 0.1103 vmlinux __copy_user_zeroing_intel_nocache
23/37408=0.061% (99.94% reduction)
Top 5 of 2.6.12.4.nt
Counted GLOBAL_POWER_EVENTS events (time during which processor is not stopped) with a unit mask of 0x01 (mandatory) count 100000
samples % app name symbol name
128392 8.0274 vmlinux __copy_user_zeroing_intel_nocache
64206 4.0143 vmlinux journal_add_journal_head
59746 3.7355 vmlinux do_get_write_access
47674 2.9807 vmlinux journal_put_journal_head
46021 2.8774 vmlinux journal_dirty_metadata
pattern9-0-cpu4-0-09011728/summary.out
Counted BSQ_CACHE_REFERENCE events (cache references seen by the bus unit) with a unit mask of 0x3f (multiple flags) count 3000
samples % app name symbol name
69755 4.2861 vmlinux __copy_user_zeroing_intel_nocache
55685 3.4215 vmlinux journal_add_journal_head
52371 3.2179 vmlinux __find_get_block
45504 2.7960 vmlinux journal_put_journal_head
36005 2.2123 vmlinux journal_stop
pattern9-0-cpu4-0-09011744/summary.out
Counted BSQ_CACHE_REFERENCE events (cache references seen by the bus unit) with a unit mask of 0x200 (read 3rd level cache miss) count 3000
samples % app name symbol name
1147 5.4994 vmlinux journal_add_journal_head
881 4.2240 vmlinux journal_dirty_data
872 4.1809 vmlinux blk_rq_map_sg
734 3.5192 vmlinux journal_commit_transaction
617 2.9582 vmlinux radix_tree_delete
pattern9-0-cpu4-0-09011731/summary.out
iozone results are
original 2.6.12.4 CPU time = 207.768 sec
cache aware CPU time = 184.783 sec
(three times run)
184.783/207.768=88.94% (11.06% reduction)
original:
pattern9-0-cpu4-0-08191720/iozone.out: CPU Utilization: Wall time 45.997 CPU time 64.527 CPU utilization 140.28 %
pattern9-0-cpu4-0-08191741/iozone.out: CPU Utilization: Wall time 46.878 CPU time 71.933 CPU utilization 153.45 %
pattern9-0-cpu4-0-08191743/iozone.out: CPU Utilization: Wall time 45.152 CPU time 71.308 CPU utilization 157.93 %
cache awre:
pattern9-0-cpu4-0-09011728/iozone.out: CPU Utilization: Wall time 44.842 CPU time 62.465 CPU utilization 139.30 %
pattern9-0-cpu4-0-09011731/iozone.out: CPU Utilization: Wall time 44.718 CPU time 59.273 CPU utilization 132.55 %
pattern9-0-cpu4-0-09011744/iozone.out: CPU Utilization: Wall time 44.367 CPU time 63.045 CPU utilization 142.10 %
Signed-off-by: Hiro Yoshioka <hyoshiok@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|