summaryrefslogtreecommitdiff
path: root/tools/perf/scripts/python/stackcollapse.py
diff options
context:
space:
mode:
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2020-08-19 21:55:05 +0200
committerPeter Zijlstra <peterz@infradead.org>2020-08-26 12:41:58 +0200
commit01ccf592362a984534371b3596d4c953da6a7bb2 (patch)
tree27cda671f00ea1ffd9a2712b00685104ef815b5a /tools/perf/scripts/python/stackcollapse.py
parent1724b95b92979a8ea8e55a4817d05b3bb7750958 (diff)
sched: Bring the PF_IO_WORKER and PF_WQ_WORKER bits closer together
The bits PF_IO_WORKER and PF_WQ_WORKER are tested together in sched_submit_work() which is considered to be a hot path. If the two bits cross the 8 or 16 bit boundary then most architecture require multiple load instructions in order to create the constant value. Also, such a value can not be encoded within the compare opcode. By moving the bit definition within the same block, the compiler can create/use one immediate value. For some reason gcc-10 on ARM64 requires both bits to be next to each other in order to issue "tst reg, val; bne label". Otherwise the result is "mov reg1, val; tst reg, reg1; bne label". Move PF_VCPU out of the way so that PF_IO_WORKER can be next to PF_WQ_WORKER. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200819195505.y3fxk72sotnrkczi@linutronix.de
Diffstat (limited to 'tools/perf/scripts/python/stackcollapse.py')
0 files changed, 0 insertions, 0 deletions