Michael S. Tsirkin 244bcc2312 mm, sched: Drop voluntary schedule from might_fault() ... might_fault() is called from functions like copy_to_user() which most callers expect to be very fast, like a couple of instructions. So functions like memcpy_toiovec() call them many times in a loop. But might_fault() calls might_sleep() and with CONFIG_PREEMPT_VOLUNTARY this results in a function call. Let's not do this - just call __might_sleep() that produces a diagnostic for sleep within atomic, but drop might_preempt(). Here's a test sending traffic between the VM and the host, host is built with CONFIG_PREEMPT_VOLUNTARY: before: incoming: 7122.77 Mb/s outgoing: 8480.37 Mb/s after: incoming: 8619.24 Mb/s outgoing: 9455.42 Mb/s As a side effect, this fixes an issue pointed out by Ingo: might_fault might schedule differently depending on PROVE_LOCKING. Now there's no preemption point in both cases, so it's consistent. Change-Id: Ic27fa27635c6f0e76ca348a9e71a21d57531394b Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1369577426-26721-10-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Git-commit: 114276ac0a3beb9c391a410349bd770653e185ce Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>		2013-10-04 14:13:01 -07:00
..
backing-dev.c	writeback: expose the bdi_wq workqueue	2013-04-01 19:08:06 -07:00
balloon_compaction.c
bootmem.c	mm: Remove __init annotations from free_bootmem_late	2013-08-22 18:09:32 -07:00
bounce.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
cleancache.c	mm: cleancache: clean up cleancache_enabled	2013-04-30 17:04:01 -07:00
compaction.c	mm: add & use zone_end_pfn() and zone_spans_pfn()	2013-02-23 17:50:20 -08:00
debug-pagealloc.c
dmapool.c
fadvise.c	teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long	2013-03-03 22:46:22 -05:00
failslab.c
filemap.c	mm: Don't use CMA pages for writes	2013-07-08 05:55:01 -07:00
filemap_xip.c	lift sb_start_write() out of ->write()	2013-04-09 14:12:56 -04:00
fremap.c	Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs"	2013-03-28 17:45:51 -07:00
frontswap.c	frontswap: fix incorrect zeroing and allocation size for frontswap_map	2013-06-12 16:29:46 -07:00
highmem.c	Some nice cleanups, and even a patch my wife did as a "live" demo for	2012-12-20 08:37:05 -08:00
huge_memory.c	mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer	2013-05-24 16:22:51 -07:00
hugetlb.c	mm: migration: add migrate_entry_wait_huge()	2013-06-12 16:29:46 -07:00
hugetlb_cgroup.c	mm/hugetlb: create hugetlb cgroup file in hugetlb_init	2012-12-18 15:02:15 -08:00
hwpoison-inject.c
init-mm.c
internal.h	mm: accelerate munlock() treatment of THP pages	2013-02-27 19:10:09 -08:00
interval_tree.c
Kconfig	kernel: Add hooks for user-accessible timers in the kernel.	2013-09-04 15:36:37 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c	hlist: drop the node parameter from iterators	2013-02-27 19:10:24 -08:00
ksm.c	ksm: fix m68k build: only NUMA needs pfn_to_nid	2013-03-08 15:05:34 -08:00
maccess.c
madvise.c	mm: madvise: complete input validation before taking lock	2013-04-29 15:54:37 -07:00
Makefile	memcg: add memory.pressure_level events	2013-04-29 15:54:38 -07:00
memblock.c	memblock: Add memblock_overlaps_memory()	2013-07-08 05:51:57 -07:00
memcontrol.c	mm: memcontrol: fix lockless reclaim hierarchy iterator	2013-06-12 16:29:46 -07:00
memory-failure.c	HWPOISON: check dirty flag to match against clean page	2013-04-29 15:54:28 -07:00
memory.c	mm, sched: Drop voluntary schedule from might_fault()	2013-10-04 14:13:01 -07:00
memory_hotplug.c	mm: make physical memory offline work	2013-07-08 05:52:01 -07:00
mempolicy.c	mm/mempolicy.c: fix sp_node_init() argument ordering	2013-03-08 15:05:34 -08:00
mempool.c
migrate.c	ion: tracing: add ftrace events for ion allocations	2013-09-04 15:52:50 -07:00
mincore.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
mlock.c	kernel: Add hooks for user-accessible timers in the kernel.	2013-09-04 15:36:37 -07:00
mm_init.c	mm: init: report on last-nid information stored in page->flags	2013-02-23 17:50:18 -08:00
mmap.c	shm: fix null pointer deref when userspace specifies invalid hugepage size	2013-05-09 14:22:47 -07:00
mmu_context.c	mm: remove old aio use_mm() comment	2013-05-07 18:38:27 -07:00
mmu_notifier.c	mm: mmu_notifier: re-fix freed page still mapped in secondary MMU	2013-05-24 16:22:51 -07:00
mmzone.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
mprotect.c	mm/mprotect.c: coding-style cleanups	2012-12-18 15:02:15 -08:00
mremap.c	mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write()	2013-02-23 17:50:17 -08:00
msync.c
nobootmem.c	mm, nobootmem: do memset() after memblock_reserve()	2013-04-29 15:54:39 -07:00
nommu.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
oom_kill.c	memcg, oom: provide more precise dump info while memcg oom happening	2013-02-23 17:50:08 -08:00
page-writeback.c	mm: make snapshotting pages for stable writes a per-bio operation	2013-04-29 15:54:33 -07:00
page_alloc.c	android/lowmemorykiller: Selectively count free CMA pages	2013-09-04 16:15:40 -07:00
page_cgroup.c	memcontrol: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:32 -08:00
page_io.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
page_isolation.c	mm: fix zone_watermark_ok_safe() accounting of isolated pages	2013-01-04 16:11:46 -08:00
pagewalk.c	mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areas	2013-05-24 16:22:53 -07:00
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
process_vm_access.c	Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys	2013-03-12 11:05:45 -07:00
quicklist.c
readahead.c	mm: pass readahead info down to the i/o scheduler	2013-08-22 18:08:28 -07:00
rmap.c	rmap: recompute pgoff for unmapping huge page	2013-04-29 15:54:28 -07:00
shmem.c	ashmem: Add shmem_set_file to mm/shmem.c	2013-07-01 13:40:20 -07:00
slab.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2013-05-07 08:42:20 -07:00
slab.h	slab: Common definition for kmem_cache_node	2013-02-01 12:32:09 +02:00
slab_common.c	slab: prevent warnings when allocating with __GFP_NOWARN	2013-06-13 10:01:58 +03:00
slob.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
slub.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2013-05-07 08:42:20 -07:00
sparse-vmemmap.c	sparse-vmemmap: specify vmemmap population range in bytes	2013-04-29 15:54:35 -07:00
sparse.c	msm: mm: Fix errors when turning on SPARSEMEM	2013-07-08 05:51:58 -07:00
swap.c	aio: don't include aio.h in sched.h	2013-05-07 20:16:25 -07:00
swap_state.c	swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion	2013-06-12 16:29:45 -07:00
swapfile.c	frontswap: fix incorrect zeroing and allocation size for frontswap_map	2013-06-12 16:29:46 -07:00
truncate.c	mm: drop vmtruncate	2012-12-20 18:46:29 -05:00
util.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
vmalloc.c	mm: Update is_vmalloc_addr to account for vmalloc savings	2013-09-05 14:51:24 -07:00
vmpressure.c	memcg: add memory.pressure_level events	2013-04-29 15:54:38 -07:00
vmscan.c	mm: vmscan: remove unused name array	2013-07-08 06:32:08 -07:00
vmstat.c	mm/vmstat: add note on safety of drain_zonestat	2013-04-29 15:54:38 -07:00