From: Tsutomu OWA <tsutomu.owa@toshiba•co.jp>
To: linuxppc-dev@ozlabs•org, linux-kernel@vger•kernel.org
Cc: mingo@elte•hu, tglx@linutronix•de
Subject: Re: [patch 4/4] powerpc 2.6.21-rt1: reduce scheduling latency by changing tlb flush size
Date: Mon, 14 May 2007 15:38:39 +0900 [thread overview]
Message-ID: <yyiveev9afk.wl@toshiba.co.jp> (raw)
In-Reply-To: <yyiwszb9asq.wl@toshiba.co.jp>
Oopps, Subject was wrong.... resending it. Sorry.
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.
As I don't know how long it takes on other platforms, it would be better to
enclose it within #ifdef CONFIG_PPC_CELLEB.
Signed-off-by: Tsutomu OWA <tsutomu.owa@toshiba•co.jp>
-- owa
diff -rup linux-2.6.21-rt1/include/asm-powerpc/tlbflush.h rt/include/asm-powerpc/tlbflush.h
--- linux-2.6.21-rt1/include/asm-powerpc/tlbflush.h 2007-04-26 12:08:32.000000000 +0900
+++ rt/include/asm-powerpc/tlbflush.h 2007-05-07 14:23:50.000000000 +0900
@@ -25,7 +25,11 @@ struct mm_struct;
#include <linux/percpu.h>
#include <asm/page.h>
+#ifdef CONFIG_PREEMPT_RT
+#define PPC64_TLB_BATCH_NR 1 /* Since tlb flush takes long time, reduce it to 1 when RT */
+#else
#define PPC64_TLB_BATCH_NR 192
+#endif /* CONFIG_PREEMPT_RT */
struct ppc64_tlb_batch {
unsigned long index;
next prev parent reply other threads:[~2007-05-14 6:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-14 6:22 [patch 0/4] powerpc 2.6.21-rt1: fix build a breakage and some minor issues Tsutomu OWA
2007-05-14 6:26 ` [patch 1/4] powerpc 2.6.21-rt1: fix a build breakage by adding __raw_*_relax() macros Tsutomu OWA
2007-05-14 6:28 ` [patch 2/4] powerpc 2.6.21-rt1: convert spinlocks to raw ones for Celleb Tsutomu OWA
2007-05-14 6:29 ` [patch 3/4] powerpc 2.6.21-rt1: add a need_resched_delayed() check Tsutomu OWA
2007-05-14 6:30 ` [patch 0/4] powerpc 2.6.21-rt1: reduce scheduling latency by changing tlb flush size Tsutomu OWA
2007-05-14 6:38 ` Tsutomu OWA [this message]
2007-05-14 6:51 ` [patch 4/4] " Thomas Gleixner
2007-05-14 7:28 ` Tsutomu OWA
2007-05-14 14:40 ` Arnd Bergmann
2007-05-15 4:12 ` Tsutomu OWA
2007-05-15 7:34 ` Benjamin Herrenschmidt
2007-05-15 6:27 ` Tsutomu OWA
2007-05-15 7:38 ` Benjamin Herrenschmidt
2007-05-15 8:08 ` Tsutomu OWA
2007-05-15 8:40 ` Benjamin Herrenschmidt
2007-05-15 7:23 ` Benjamin Herrenschmidt
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