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![]() RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk> |
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.. | ||
budget.c | ||
commit.c | ||
compress.c | ||
debug.c | ||
debug.h | ||
dir.c | ||
file.c | ||
find.c | ||
gc.c | ||
io.c | ||
ioctl.c | ||
journal.c | ||
Kconfig | ||
key.h | ||
log.c | ||
lprops.c | ||
lpt.c | ||
lpt_commit.c | ||
Makefile | ||
master.c | ||
misc.h | ||
orphan.c | ||
recovery.c | ||
replay.c | ||
sb.c | ||
scan.c | ||
shrinker.c | ||
super.c | ||
tnc.c | ||
tnc_commit.c | ||
tnc_misc.c | ||
ubifs-media.h | ||
ubifs.h | ||
xattr.c |