From: Jeff Dike <jdike@addtoit.com>
To: Andrew Morton <akpm@osdl.org>
Cc: uml-devel <user-mode-linux-devel@lists.sourceforge.net>,
LKML <linux-kernel@vger.kernel.org>,
caker@linode.com
Subject: [uml-devel] [PATCH 3/3] UML - An idle system should have zero load average
Date: Fri, 4 May 2007 13:39:58 -0400 [thread overview]
Message-ID: <20070504173958.GA7948@c2.user-mode-linux.org> (raw)
The ever-vigilant users of linode.com noticed that an idle 2.6 UML has
a persistent load average of ~.4.
It turns out that because the UML timer handler processed softirqs
before actually delivering the tick, the tick was counted in the
context of the idle thread about half the time.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
--
arch/um/kernel/time.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.21-mm/arch/um/kernel/time.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/kernel/time.c 2007-05-04 12:40:52.000000000 -0400
+++ linux-2.6.21-mm/arch/um/kernel/time.c 2007-05-04 13:13:39.000000000 -0400
@@ -177,6 +177,8 @@ int do_settimeofday(struct timespec *tv)
void timer_handler(int sig, union uml_pt_regs *regs)
{
+ if(current_thread->cpu == 0)
+ timer_irq(regs);
local_irq_disable();
irq_enter();
update_process_times(CHOOSE_MODE(
@@ -184,6 +186,4 @@ void timer_handler(int sig, union uml_pt
(regs)->skas.is_user));
irq_exit();
local_irq_enable();
- if(current_thread->cpu == 0)
- timer_irq(regs);
}
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WARNING: multiple messages have this Message-ID (diff)
From: Jeff Dike <jdike@addtoit.com>
To: Andrew Morton <akpm@osdl.org>
Cc: caker@linode.com, LKML <linux-kernel@vger.kernel.org>,
uml-devel <user-mode-linux-devel@lists.sourceforge.net>
Subject: [PATCH 3/3] UML - An idle system should have zero load average
Date: Fri, 4 May 2007 13:39:58 -0400 [thread overview]
Message-ID: <20070504173958.GA7948@c2.user-mode-linux.org> (raw)
The ever-vigilant users of linode.com noticed that an idle 2.6 UML has
a persistent load average of ~.4.
It turns out that because the UML timer handler processed softirqs
before actually delivering the tick, the tick was counted in the
context of the idle thread about half the time.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
--
arch/um/kernel/time.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.21-mm/arch/um/kernel/time.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/kernel/time.c 2007-05-04 12:40:52.000000000 -0400
+++ linux-2.6.21-mm/arch/um/kernel/time.c 2007-05-04 13:13:39.000000000 -0400
@@ -177,6 +177,8 @@ int do_settimeofday(struct timespec *tv)
void timer_handler(int sig, union uml_pt_regs *regs)
{
+ if(current_thread->cpu == 0)
+ timer_irq(regs);
local_irq_disable();
irq_enter();
update_process_times(CHOOSE_MODE(
@@ -184,6 +186,4 @@ void timer_handler(int sig, union uml_pt
(regs)->skas.is_user));
irq_exit();
local_irq_enable();
- if(current_thread->cpu == 0)
- timer_irq(regs);
}
next reply other threads:[~2007-05-04 17:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-04 17:39 Jeff Dike [this message]
2007-05-04 17:39 ` [PATCH 3/3] UML - An idle system should have zero load average Jeff Dike
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