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| author | Christophe Leroy | 2022-03-14 11:27:35 +0100 |
|---|---|---|
| committer | Peter Zijlstra | 2022-04-05 09:59:38 +0200 |
| commit | 5517d500829c683a358a8de04ecb2e28af629ae5 (patch) | |
| tree | da7f5fefbdd46e59e7a62647e0b10277e0245b3e /fs/timerfd.c | |
| parent | 8fd4ddda2f49a66bf5dd3d0c01966c4b1971308b (diff) | |
static_call: Properly initialise DEFINE_STATIC_CALL_RET0()
When a static call is updated with __static_call_return0() as target,
arch_static_call_transform() set it to use an optimised set of
instructions which are meant to lay in the same cacheline.
But when initialising a static call with DEFINE_STATIC_CALL_RET0(),
we get a branch to the real __static_call_return0() function instead
of getting the optimised setup:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 4b ff ff f4 b c00d8114 <__static_call_return0>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Add ARCH_DEFINE_STATIC_CALL_RET0_TRAMP() defined by each architecture
to setup the optimised configuration, and rework
DEFINE_STATIC_CALL_RET0() to call it:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 48 00 00 14 b c00d8134 <__SCT__perf_snapshot_branch_stack+0x14>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/1e0a61a88f52a460f62a58ffc2a5f847d1f7d9d8.1647253456.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'fs/timerfd.c')
0 files changed, 0 insertions, 0 deletions