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| author | Borislav Petkov (AMD) <bp@alien8.de> | 2023-01-25 08:50:13 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-01-25 10:32:06 +0100 |
| commit | ebd3ad60a688131de7df1dd05fd2d7c57f542268 (patch) | |
| tree | d8bf8866cd972dac8a3a8aa5654b171de8ba7010 /arch/x86/mm | |
| parent | Linux 6.2-rc5 (diff) | |
| download | linux-ebd3ad60a688131de7df1dd05fd2d7c57f542268.tar.xz linux-ebd3ad60a688131de7df1dd05fd2d7c57f542268.zip | |
x86/cpu: Use cpu_feature_enabled() when checking global pages support
X86_FEATURE_PGE determines whether the CPU has enabled global page
translations support. Use the faster cpu_feature_enabled() check to
shave off some more cycles when flushing all TLB entries, including the
global ones.
What this practically saves is:
mov 0x82eb308(%rip),%rax # 0xffffffff8935bec8 <boot_cpu_data+40>
test $0x20,%ah
... which test the bit. Not a lot, but TLB flushing is a timing-sensitive
path, so anything to make it even faster.
No functional changes.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230125075013.9292-1-bp@alien8.de
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/tlb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index c1e31e9a85d7..92d73ccede70 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1205,7 +1205,7 @@ void __flush_tlb_all(void) */ VM_WARN_ON_ONCE(preemptible()); - if (boot_cpu_has(X86_FEATURE_PGE)) { + if (cpu_feature_enabled(X86_FEATURE_PGE)) { __flush_tlb_global(); } else { /* |