Minchan Kim 240c879f20 writeback: avoid unnecessary determine_dirtyable_memory call ... I think determine_dirtyable_memory() is a rather costly function since it need many atomic reads for gathering zone/global page state. But when we use vm_dirty_bytes && dirty_background_bytes, we don't need that costly calculation. This patch eliminates such unnecessary overhead. NOTE : newly added if condition might add overhead in normal path. But it should be _really_ small because anyway we need the access both vm_dirty_bytes and dirty_background_bytes so it is likely to hit the cache. [akpm@linux-foundation.org: fix used-uninitialised warning] Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2011-01-13 17:32:38 -08:00
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backing-dev.c
bootmem.c
bounce.c
compaction.c
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap.c
filemap_xip.c
fremap.c
highmem.c
hugetlb.c
hwpoison-inject.c
init-mm.c
internal.h
Kconfig
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
maccess.c
madvise.c
Makefile
memblock.c
memcontrol.c
memory-failure.c
memory.c
memory_hotplug.c
mempolicy.c
mempool.c
migrate.c
mincore.c
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c
page-writeback.c	writeback: avoid unnecessary determine_dirtyable_memory call	2011-01-13 17:32:38 -08:00
page_alloc.c
page_cgroup.c
page_io.c
page_isolation.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
prio_tree.c
quicklist.c
readahead.c
rmap.c
shmem.c
slab.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap_state.c
swapfile.c
thrash.c
truncate.c
util.c
vmalloc.c
vmscan.c
vmstat.c