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| author | Long Li <leo.lilong@huawei.com> | 2024-04-16 09:16:28 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-05-06 03:53:38 +0300 |
| commit | ba591801a3df861b3b327f6122b9de4ef213aae6 (patch) | |
| tree | 1bb2326efbe66f1eaca201e42a3f1849157de644 /lib | |
| parent | 2aa339120c7dfe834297a77b13b1a98e12842932 (diff) | |
| download | linux-ba591801a3df861b3b327f6122b9de4ef213aae6.tar.xz | |
xarray: inline xas_descend to improve performance
The commit 63b1898fffcd ("XArray: Disallow sibling entries of nodes")
modified the xas_descend function in such a way that it was no longer
being compiled as an inline function, because it increased the size of
xas_descend(), and the compiler no longer optimizes it as inline. This
had a negative impact on performance, xas_descend is called frequently to
traverse downwards in the xarray tree, making it a hot function.
Inlining xas_descend has been shown to significantly improve performance
by approximately 4.95% in the iozone write test.
Machine: Intel(R) Xeon(R) Gold 6240 CPU @ 2.60GHz
#iozone i 0 -i 1 -s 64g -r 16m -f /test/tmptest
Before this patch:
kB reclen write rewrite read reread
67108864 16384 2230080 3637689 6315197 5496027
After this patch:
kB reclen write rewrite read reread
67108864 16384 2340360 3666175 6272401 5460782
Percentage change:
4.95% 0.78% -0.68% -0.64%
This patch introduces inlining to the xas_descend function. While this
change increases the size of lib/xarray.o, the performance gains in
critical workloads make this an acceptable trade-off.
Size comparison before and after patch:
.text .data .bss file
0x3502 0 0 lib/xarray.o.before
0x3602 0 0 lib/xarray.o.after
Link: https://lkml.kernel.org/r/20240416061628.3768901-1-leo.lilong@huawei.com
Signed-off-by: Long Li <leo.lilong@huawei.com>
Cc: Hou Tao <houtao1@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: yangerkun <yangerkun@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/xarray.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/lib/xarray.c b/lib/xarray.c index da79128ad754..1c87d871cacf 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -200,7 +200,8 @@ static void *xas_start(struct xa_state *xas) return entry; } -static void *xas_descend(struct xa_state *xas, struct xa_node *node) +static __always_inline void *xas_descend(struct xa_state *xas, + struct xa_node *node) { unsigned int offset = get_offset(xas->xa_index, node); void *entry = xa_entry(xas->xa, node, offset); |