60c371bc75
The POSIX_FADV_NOREUSE hint means "the application will use this range of the file a single time". It seems to be intended that the implementation will use this hint to perform drop-behind of that part of the file when the application gets around to reading or writing it. However for reasons which aren't obvious (or sane?) I mapped POSIX_FADV_NOREUSE onto POSIX_FADV_WILLNEED. ie: it does readahead. That's daft. So for now, make POSIX_FADV_NOREUSE a no-op. This is a non-back-compatible change. If someone was using POSIX_FADV_NOREUSE to perform readahead, they lose. The likelihood is low. If/when we later implement POSIX_FADV_NOREUSE things will get interesting - to do it fully we'll need to maintain file offset/length ranges and peform all sorts of complex tricks, and managing the lifetime of those ranges' data structures will be interesting.. A sensible implementation would probably ignore the file range and would simply mark the entire file as needing some form of drop-behind treatment. Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
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.. | ||
bootmem.c | ||
fadvise.c | ||
filemap_xip.c | ||
filemap.c | ||
filemap.h | ||
fremap.c | ||
highmem.c | ||
hugetlb.c | ||
internal.h | ||
Kconfig | ||
madvise.c | ||
Makefile | ||
memory_hotplug.c | ||
memory.c | ||
mempolicy.c | ||
mempool.c | ||
migrate.c | ||
mincore.c | ||
mlock.c | ||
mmap.c | ||
mmzone.c | ||
mprotect.c | ||
mremap.c | ||
msync.c | ||
nommu.c | ||
oom_kill.c | ||
page_alloc.c | ||
page_io.c | ||
page-writeback.c | ||
pdflush.c | ||
prio_tree.c | ||
readahead.c | ||
rmap.c | ||
shmem.c | ||
slab.c | ||
slob.c | ||
sparse.c | ||
swap_state.c | ||
swap.c | ||
swapfile.c | ||
thrash.c | ||
tiny-shmem.c | ||
truncate.c | ||
util.c | ||
vmalloc.c | ||
vmscan.c | ||
vmstat.c |