Re: 2.6.16-rc1-mm4 i386 atomic operations broken on SMP (in modules at least)

[Chuck Ebbert]

In-Reply-To: <20060202135205.08d91b76.akpm@xxxxxxxx>

On Thu, 2 Feb 2006 at 13:52:05 -0800, Andrew Morton wrote:

> Chuck Ebbert <76306.1226@xxxxxxxxxxxxxx> wrote:
> > 
> > SMP alternatives is re-using the constant_tsc X86 feature bit.
> > 
> 
> Darn, how did you spot that?

I went looking for which bit represented X86_FEATURE_UP and there
it was...

>
> Should `feature_up' appear in /proc/cpuinfo?

Probably.  The bug would have been nearly impossible if that had
been done to begin with.


i386: show x86 feature "up" in cpuinfo

Show feature bit "up" (SMP kernel running on uniprocessor) in
/proc/cpuinfo.

Signed-off-by: Chuck Ebbert <76306.1226@xxxxxxxxxxxxxx>

--- 2.6.16-rc1-mm4-386.orig/arch/i386/kernel/cpu/proc.c
+++ 2.6.16-rc1-mm4-386/arch/i386/kernel/cpu/proc.c
@@ -40,7 +40,7 @@ static int show_cpuinfo(struct seq_file 
 		/* Other (Linux-defined) */
 		"cxmmx", "k6_mtrr", "cyrix_arr", "centaur_mcr",
 		NULL, NULL, NULL, NULL,
-		"constant_tsc", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+		"constant_tsc", "up", NULL, NULL, NULL, NULL, NULL, NULL,
 		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 
-- 
Chuck
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