mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-14 17:57:05 +07:00
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> |
||
|---|---|---|
| .. | ||
| 8xx | ||
| 40x | ||
| 44x | ||
| 52xx | ||
| 82xx | ||
| 83xx | ||
| 85xx | ||
| 86xx | ||
| 512x | ||
| amigaone | ||
| cell | ||
| chrp | ||
| embedded6xx | ||
| iseries | ||
| maple | ||
| pasemi | ||
| powermac | ||
| prep | ||
| ps3 | ||
| pseries | ||
| fsl_uli1575.c | ||
| Kconfig | ||
| Kconfig.cputype | ||
| Makefile | ||