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| author | Heiko Carstens <hca@linux.ibm.com> | 2026-01-13 20:43:58 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2026-01-17 15:52:49 +0100 |
| commit | 23ba7d31633da6b0706b4154e4eb74cdfab710ef (patch) | |
| tree | 9e43697551545e4bdad6a207b9bf02f38bdf88ba /Documentation/features/debug/stackprotector | |
| parent | 6cce3609a1e0dedeef9b4bfdc87d0d4692f691d7 (diff) | |
| download | linux-23ba7d31633da6b0706b4154e4eb74cdfab710ef.tar.gz linux-23ba7d31633da6b0706b4154e4eb74cdfab710ef.zip | |
s390/preempt: Optimize __preemp_count_add()/__preempt_count_sub()
Provide an inline assembly using alternatives to avoid the need of a
base register due to relocatable lowcore when adding or subtracting
small constants from preempt_count.
Main user is preempt_disable(), which subtracts one from
preempt_count. With this the generated code changes from
10012c: a7 b9 00 00 lghi %r11,0
100130: eb 01 b3 a8 00 6a asi 936(%r11),1
to something like this:
10012c: eb 01 03 a8 00 6a asi 936,1
Kernel image size is reduced by 13kb (bloat-o-meter -t, defconfig, gcc15).
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'Documentation/features/debug/stackprotector')
0 files changed, 0 insertions, 0 deletions