Re: [patch 4/4] powerpc 2.6.21-rt1: reduce scheduling latency by changing tlb flush size

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



At Mon, 14 May 2007 08:51:46 +0200, Thomas Gleixner wrote:

> On Mon, 2007-05-14 at 15:38 +0900, Tsutomu OWA wrote:
> > As I don't know how long it takes on other platforms, it would be better to 
> > enclose it within #ifdef CONFIG_PPC_CELLEB.
> 
> Yes, that might be appropriate. Can you add this and resend please ?

  Certainly, and thanks for your comment.

To reduce scheduling latecy by changing tlb flush size to 1.
Since tlb flush on Celleb is done by calling (an) expensive hypervisor call(s), 
it takes a long time to flush tlbs and causes scheduing latency.

Signed-off-by: Tsutomu OWA <[email protected]>
-- owa

--- linux-2.6.21-rt1/include/asm-powerpc/tlbflush.h	2007-04-26 12:08:32.000000000 +0900
+++ rt/include/asm-powerpc/tlbflush.h	2007-05-14 16:12:47.000000000 +0900
@@ -25,7 +25,12 @@ struct mm_struct;
 #include <linux/percpu.h>
 #include <asm/page.h>
 
+#if defined(CONFIG_PPC_CELLEB) && defined(CONFIG_PREEMPT_RT)
+/* Since tlb flush takes long time on Celleb, reduce it to 1 when Celleb && RT */
+#define PPC64_TLB_BATCH_NR 1
+#else
 #define PPC64_TLB_BATCH_NR 192
+#endif /* defined(CONFIG_PPC_CELLEB) && defined(CONFIG_PREEMPT_RT) */
 
 struct ppc64_tlb_batch {
 	unsigned long index;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux