Messages in this thread Patch in this message | | | Date | Thu, 2 Feb 2006 13:12:37 -0500 | From | Chuck Ebbert <> | Subject | Re: 2.6.16-rc1-mm4 i386 atomic operations broken on SMP (in modules at least) |
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In-Reply-To: <17377.24090.486443.865483@cse.unsw.edu.au>
On Thu, 2 Feb 2006 at 12:19:22 +1100, Neil Brown wrote:
> My guess is there is there is something wrong with the 'alternative' > stuff which strips out the lock prefix, but I couldn't see anything > obviously wrong. The CPUs don't have FEATURE_UP (see below) so it > cannot possibly be removing the 'lock' prefix... but it certainly acts > like it is.
Look closer:
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca > cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm > constant_tsc pni monitor ds_cpl cid xtpr ^^^^^^^^^^^^
SMP alternatives is re-using the constant_tsc X86 feature bit.
--- 2.6.16-rc1-mm4-386.orig/include/asm-i386/cpufeature.h +++ 2.6.16-rc1-mm4-386/include/asm-i386/cpufeature.h @@ -71,7 +71,7 @@ #define X86_FEATURE_P4 (3*32+ 7) /* P4 */ #define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */ -#define X86_FEATURE_UP (3*32+ 8) /* smp kernel running on up */ +#define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ -- Chuck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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