fa0d7e3de6
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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| .. | ||
| .gitignore | ||
| Makefile | ||
| backing_ops.c | ||
| context.c | ||
| coredump.c | ||
| fault.c | ||
| file.c | ||
| gang.c | ||
| hw_ops.c | ||
| inode.c | ||
| lscsa_alloc.c | ||
| run.c | ||
| sched.c | ||
| spu_restore.c | ||
| spu_restore_crt0.S | ||
| spu_restore_dump.h_shipped | ||
| spu_save.c | ||
| spu_save_crt0.S | ||
| spu_save_dump.h_shipped | ||
| spu_utils.h | ||
| spufs.h | ||
| sputrace.h | ||
| switch.c | ||
| syscalls.c | ||