]> err.no Git - linux-2.6/commit
[PATCH] x86: rewrite SMP TSC sync code
authorIngo Molnar <mingo@elte.hu>
Fri, 16 Feb 2007 09:27:34 +0000 (01:27 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 16 Feb 2007 16:13:57 +0000 (08:13 -0800)
commit95492e4646e5de8b43d9a7908d6177fb737b61f0
treeae25cd206ca76f78d50ac2a206ef012e0ab1d9df
parent92c7e00254b2d0efc1e36ac3e45474ce1871b6b2
[PATCH] x86: rewrite SMP TSC sync code

make the TSC synchronization code more robust, and unify it between x86_64 and
i386.

The biggest change is the removal of the 'fix up TSCs' code on x86_64 and
i386, in some rare cases it was /causing/ time-warps on SMP systems.

The new code only checks for TSC asynchronity - and if it can prove a
time-warp (if it can observe the TSC going backwards when going from one CPU
to another within a critical section), then the TSC clock-source is turned
off.

The TSC synchronization-checking code also got moved into a separate file.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
12 files changed:
arch/i386/kernel/Makefile
arch/i386/kernel/smpboot.c
arch/i386/kernel/tsc.c
arch/i386/kernel/tsc_sync.c [new file with mode: 0644]
arch/x86_64/kernel/Makefile
arch/x86_64/kernel/smpboot.c
arch/x86_64/kernel/time.c
arch/x86_64/kernel/tsc_sync.c [new file with mode: 0644]
include/asm-i386/tsc.h
include/asm-x86_64/proto.h
include/asm-x86_64/timex.h
include/asm-x86_64/tsc.h [new file with mode: 0644]