path: root/arch/x86/kernel
diff options
authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2008-08-15 12:56:59 -0400
committerH. Peter Anvin <hpa@zytor.com>2008-08-15 12:51:11 -0700
commit5bbd4c3724008c93cf3efdfc38a3402e245ab506 (patch)
tree5b74f2b70396f2cf808b368d415ae444fe94bfac /arch/x86/kernel
parent1f49a2c2aeb22d5abc6d4ea574ff63d37ca55fbe (diff)
x86: spinlock use LOCK_PREFIX
Since we are now using DS prefixes instead of NOP to remove LOCK prefixes, there is no longer any problems with instruction boundaries moving around. * Linus Torvalds (torvalds@linux-foundation.org) wrote: > > > On Thu, 14 Aug 2008, Mathieu Desnoyers wrote: > > > > Changing the 0x90 (single-byte nop) currently used into a 0x3E DS segment > > override prefix should fix this issue. Since the default of the atomic > > instructions is to use the DS segment anyway, it should not affect the > > behavior. > > Ok, so I think this is an _excellent_ patch, but I'd like to also then use > LOCK_PREFIX in include/asm-x86/futex.h. > > See commit 9d55b9923a1b7ea8193b8875c57ec940dc2ff027. > > Linus Unless there a rationale for this, I think these be changed to LOCK_PREFIX too. grep "lock ;" include/asm-x86/spinlock.h "lock ; cmpxchgw %w1,%2\n\t" asm volatile("lock ; xaddl %0, %1\n" "lock ; cmpxchgl %1,%2\n\t" Applies to 2.6.27-rc2. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> CC: Linus Torvalds <torvalds@linux-foundation.org> CC: H. Peter Anvin <hpa@zytor.com> CC: Jeremy Fitzhardinge <jeremy@goop.org> CC: Roland McGrath <roland@redhat.com> CC: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> CC: Steven Rostedt <srostedt@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Peter Zijlstra <peterz@infradead.org> CC: Andrew Morton <akpm@linux-foundation.org> CC: David Miller <davem@davemloft.net> CC: Ulrich Drepper <drepper@redhat.com> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Gregory Haskins <ghaskins@novell.com> CC: Arnaldo Carvalho de Melo <acme@redhat.com> CC: "Luis Claudio R. Goncalves" <lclaudio@uudg.org> CC: Clark Williams <williams@redhat.com> CC: Christoph Lameter <cl@linux-foundation.org> CC: Andi Kleen <andi@firstfloor.org> CC: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel')
0 files changed, 0 insertions, 0 deletions