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| author | Chuck Lever <chuck.lever@oracle.com> | 2024-02-17 23:24:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-30 10:48:59 +0300 |
| commit | 3d8babce24a7bad53dacae3182b071700cc28940 (patch) | |
| tree | 9933171b0613c01a14591cc36d4552d13e1d32c7 /include/linux/fs.h | |
| parent | c1ab3bf4969f041009a078a1d15e9c2cf96318a2 (diff) | |
| download | linux-3d8babce24a7bad53dacae3182b071700cc28940.tar.xz | |
libfs: Convert simple directory offsets to use a Maple Tree
[ Upstream commit 0e4a862174f2a8d1653a8a9cf0815020e1d3af24 ]
Test robot reports:
> kernel test robot noticed a -19.0% regression of aim9.disk_src.ops_per_sec on:
>
> commit: a2e459555c5f9da3e619b7e47a63f98574dc75f1 ("shmem: stable directory offsets")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
Feng Tang further clarifies that:
> ... the new simple_offset_add()
> called by shmem_mknod() brings extra cost related with slab,
> specifically the 'radix_tree_node', which cause the regression.
Willy's analysis is that, over time, the test workload causes
xa_alloc_cyclic() to fragment the underlying SLAB cache.
This patch replaces the offset_ctx's xarray with a Maple Tree in the
hope that Maple Tree's dense node mode will handle this scenario
more scalably.
In addition, we can widen the simple directory offset maximum to
signed long (as loff_t is also signed).
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202309081306.3ecb3734-oliver.sang@intel.com
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/170820145616.6328.12620992971699079156.stgit@91.116.238.104.host.secureserver.net
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: 23cdd0eed3f1 ("libfs: Fix simple_offset_rename_exchange()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index e684b9fa6481..3350f875ca91 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -43,6 +43,7 @@ #include <linux/cred.h> #include <linux/mnt_idmapping.h> #include <linux/slab.h> +#include <linux/maple_tree.h> #include <asm/byteorder.h> #include <uapi/linux/fs.h> @@ -3259,8 +3260,8 @@ extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, const void __user *from, size_t count); struct offset_ctx { - struct xarray xa; - u32 next_offset; + struct maple_tree mt; + unsigned long next_offset; }; void simple_offset_init(struct offset_ctx *octx); |