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| author | Peter Zijlstra <peterz@infradead.org> | 2021-05-06 22:34:05 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-05-12 15:54:56 +0300 |
| commit | ab3257042c26d0cd44793c741e2f89bf38b21fe8 (patch) | |
| tree | 1b20008657d1d7ee5681252672e9b7a5cab58431 /tools/perf/scripts/python/export-to-sqlite.py | |
| parent | e2d9494beff21a26438eb611c260b8a6c2dc4dbf (diff) | |
| download | linux-ab3257042c26d0cd44793c741e2f89bf38b21fe8.tar.xz | |
jump_label, x86: Allow short NOPs
Now that objtool is able to rewrite jump_label instructions, have the
compiler emit a JMP, such that it can decide on the optimal encoding,
and set jump_entry::key bit1 to indicate that objtool should rewrite
the instruction to a matching NOP.
For x86_64-allyesconfig this gives:
jl\ NOP JMP
short: 22997 124
long: 30874 90
IOW, we save (22997+124) * 3 bytes of kernel text in hotpaths.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194158.216763632@infradead.org
Diffstat (limited to 'tools/perf/scripts/python/export-to-sqlite.py')
0 files changed, 0 insertions, 0 deletions