Messages in this thread Patch in this message | | | Date | Tue, 13 Jun 2006 21:53:52 +0200 | From | Andreas Mohr <> | Subject | [PATCH -mm] i386: cpu_relax() smp.c (was: [RFC -mm] more cpu_relax() places?) |
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Hi,
On Mon, Jun 12, 2006 at 08:37:43PM +0200, Andreas Mohr wrote: > Hi all, > > while reviewing 2.6.17-rc6-mm1, I found some places that might > want to make use of cpu_relax() in order to not block secondary > pipelines while busy-polling (probably especially useful on SMT CPUs):
OK, no replies arguing against anything, thus patch follow-up. ;) (no. 1 of 3)
Signed-off-by: Andreas Mohr <andi@lisas.de>
diff -urN linux-2.6.17-rc6-mm2.orig/arch/i386/kernel/smp.c linux-2.6.17-rc6-mm2.my/arch/i386/kernel/smp.c --- linux-2.6.17-rc6-mm2.orig/arch/i386/kernel/smp.c 2006-06-08 10:38:04.000000000 +0200 +++ linux-2.6.17-rc6-mm2.my/arch/i386/kernel/smp.c 2006-06-13 19:33:22.000000000 +0200 @@ -388,9 +388,11 @@ */ send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR); - while (!cpus_empty(flush_cpumask)) + while (!cpus_empty(flush_cpumask)) { + cpu_relax(); /* nothing. lockup detection does not belong here */ mb(); + } flush_mm = NULL; flush_va = 0; - 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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