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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2017-04-19 15:56:24 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-06-02 12:10:24 +0300 |
| commit | e8de85ca32f572f5dee00733022d8a1ce87aed3d (patch) | |
| tree | a9ae6517de277020b14ea2fa0244fc04fdbd6c79 /arch/powerpc/mm | |
| parent | 9affa9e228d3ece66ed322909e84cfb08f6c4c64 (diff) | |
| download | linux-e8de85ca32f572f5dee00733022d8a1ce87aed3d.tar.xz | |
powerpc/mm: Only call store_updates_sp() on stores in do_page_fault()
Function store_updates_sp() checks whether the faulting
instruction is a store updating r1. Therefore we can limit its calls
to store exceptions.
This patch is an improvement of commit a7a9dcd882a67 ("powerpc: Avoid
taking a data miss on every userspace instruction miss")
With the same microbenchmark app, run with 500 as argument, on an
MPC885 we get:
Before this patch: 152000 DTLB misses
After this patch: 147000 DTLB misses
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 3a7d580fdc59..67fefb59d40e 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -287,7 +287,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, * can result in fault, which will cause a deadlock when called with * mmap_sem held */ - if (!is_exec && user_mode(regs)) + if (is_write && user_mode(regs)) store_update_sp = store_updates_sp(regs); if (user_mode(regs)) |