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| author | Peter Zijlstra <peterz@infradead.org> | 2017-05-02 13:22:07 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-15 10:15:15 +0200 |
| commit | 59eaef78bfea88fcbbd7b9b48ccf513aae1522c3 (patch) | |
| tree | eb668f47caa16eab8c3ac280654a28d25890ddee /arch/x86/include/asm/timer.h | |
| parent | x86/tsc: Provide 'tsc=unstable' boot parameter (diff) | |
| download | linux-59eaef78bfea88fcbbd7b9b48ccf513aae1522c3.tar.xz linux-59eaef78bfea88fcbbd7b9b48ccf513aae1522c3.zip | |
x86/tsc: Remodel cyc2ns to use seqcount_latch()
Replace the custom multi-value scheme with the more regular
seqcount_latch() scheme. Along with scrapping a lot of lines, the latch
scheme is better documented and used in more places.
The immediate benefit however is not being limited on the update side.
The current code has a limit where the writers block which is hit by
future changes.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/timer.h')
| -rw-r--r-- | arch/x86/include/asm/timer.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h index 27e9f9d769b8..2016962103df 100644 --- a/arch/x86/include/asm/timer.h +++ b/arch/x86/include/asm/timer.h @@ -29,11 +29,9 @@ struct cyc2ns_data { u32 cyc2ns_mul; u32 cyc2ns_shift; u64 cyc2ns_offset; - u32 __count; - /* u32 hole */ -}; /* 24 bytes -- do not grow */ +}; /* 16 bytes */ -extern struct cyc2ns_data *cyc2ns_read_begin(void); -extern void cyc2ns_read_end(struct cyc2ns_data *); +extern void cyc2ns_read_begin(struct cyc2ns_data *); +extern void cyc2ns_read_end(void); #endif /* _ASM_X86_TIMER_H */ |