diff options
| author | Andrew Morton <akpm@osdl.org> | 2006-01-08 01:00:39 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-08 20:12:40 -0800 |
| commit | 9d0243bca345d5ce25d3f4b74b7facb3a6df1232 (patch) | |
| tree | a3a0a763bf83a483282dc1c3caab587941a98fc2 /include | |
| parent | bec6b0c89b234090681a4516e20ac5debe3e7c59 (diff) | |
[PATCH] drop-pagecache
Add /proc/sys/vm/drop_caches. When written to, this will cause the kernel to
discard as much pagecache and/or reclaimable slab objects as it can. THis
operation requires root permissions.
It won't drop dirty data, so the user should run `sync' first.
Caveats:
a) Holds inode_lock for exorbitant amounts of time.
b) Needs to be taught about NUMA nodes: propagate these all the way through
so the discarding can be controlled on a per-node basis.
This is a debugging feature: useful for getting consistent results between
filesystem benchmarks. We could possibly put it under a config option, but
it's less than 300 bytes.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 7 | ||||
| -rw-r--r-- | include/linux/sysctl.h | 1 |
2 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index bc01fff3aa01..83c651f25188 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1036,5 +1036,12 @@ int in_gate_area_no_task(unsigned long addr); /* /proc/<pid>/oom_adj set to -17 protects from the oom-killer */ #define OOM_DISABLE -17 +int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *, + void __user *, size_t *, loff_t *); +int shrink_slab(unsigned long scanned, gfp_t gfp_mask, + unsigned long lru_pages); +void drop_pagecache(void); +void drop_slab(void); + #endif /* __KERNEL__ */ #endif /* _LINUX_MM_H */ diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index a9b80fc7f0f3..4cd267fe87ec 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -180,6 +180,7 @@ enum VM_VFS_CACHE_PRESSURE=26, /* dcache/icache reclaim pressure */ VM_LEGACY_VA_LAYOUT=27, /* legacy/compatibility virtual address space layout */ VM_SWAP_TOKEN_TIMEOUT=28, /* default time for token time out */ + VM_DROP_PAGECACHE=29, /* int: nuke lots of pagecache */ }; |