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| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-05-11 18:52:06 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 09:39:13 +0300 |
| commit | 8bcbde5480f9777f8b74d71493722c663e22c21b (patch) | |
| tree | 27f50af6fb09789e5b9310ff8aa16784bf9815ae /include/linux/sched.h | |
| parent | 3e51f3c4004c9b01f66da03214a3e206f5ed627b (diff) | |
| download | linux-8bcbde5480f9777f8b74d71493722c663e22c21b.tar.xz | |
sched/preempt, mm/fault: Count pagefault_disable() levels in pagefault_disabled
Until now, pagefault_disable()/pagefault_enabled() used the preempt
count to track whether in an environment with pagefaults disabled (can
be queried via in_atomic()).
This patch introduces a separate counter in task_struct to count the
level of pagefault_disable() calls. We'll keep manipulating the preempt
count to retain compatibility to existing pagefault handlers.
It is now possible to verify whether in a pagefault_disable() envionment
by calling pagefault_disabled(). In contrast to in_atomic() it will not
be influenced by preempt_enable()/preempt_disable().
This patch is based on a patch from Ingo Molnar.
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-2-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index c53a1784d7a9..dd07ac03f82a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1788,6 +1788,7 @@ struct task_struct { #ifdef CONFIG_DEBUG_ATOMIC_SLEEP unsigned long task_state_change; #endif + int pagefault_disabled; }; /* Future-safe accessor for struct task_struct's cpus_allowed. */ |