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| author | Thomas Gleixner <[email protected]> | 2020-03-08 18:07:17 +0000 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2020-03-09 21:33:09 +0000 |
| commit | 8d67743653dce5a0e7aa500fcccb237cde7ad88e (patch) | |
| tree | 777ab98cc4f98ecf6d7ed407672811a91a57e9d5 /tools/perf/scripts/python | |
| parent | futex: Fix inode life-time issue (diff) | |
| download | kernel-8d67743653dce5a0e7aa500fcccb237cde7ad88e.tar.gz kernel-8d67743653dce5a0e7aa500fcccb237cde7ad88e.zip | |
futex: Unbreak futex hashing
The recent futex inode life time fix changed the ordering of the futex key
union struct members, but forgot to adjust the hash function accordingly,
As a result the hashing omits the leading 64bit and even hashes beyond the
futex key causing a bad hash distribution which led to a ~100% performance
regression.
Hand in the futex key pointer instead of a random struct member and make
the size calculation based of the struct offset.
Fixes: 8019ad13ef7f ("futex: Fix inode life-time issue")
Reported-by: Rong Chen <[email protected]>
Decoded-by: Linus Torvalds <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Rong Chen <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Diffstat (limited to 'tools/perf/scripts/python')
0 files changed, 0 insertions, 0 deletions