path: root/arch/x86/kernel
diff options
authorJoe Korty <joe.korty@ccur.com>2008-08-27 10:35:06 -0400
committerIngo Molnar <mingo@elte.hu>2008-08-28 11:29:48 +0200
commit2c7e9fd4c6cb7f4b0bc7162e9a30847e51a1ca1b (patch)
tree66b3e67895a115af4ae79ad6e8dbe36957c5d3f7 /arch/x86/kernel
parent4c246edd2550304df5b766cc841584b2bb058843 (diff)
x86: make poll_idle behave more like the other idle methods
Make poll_idle() behave more like the other idle methods. Currently, poll_idle() returns immediately. The other idle methods all wait indefinately for some condition to come true before returning. poll_idle should emulate these other methods and also wait for a return condition, in this case, for need_resched() to become 'true'. Without this delay the idle loop spends all of its time in the outer loop that calls poll_idle. This outer loop, these days, does real work, some of it under rcu locks. That work should only be done when idle is entered and when idle exits, not continuously while idle is spinning. Signed-off-by: Joe Korty <joe.korty@ccur.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 7fc4d5b0a6a..4e09d26748c 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -185,7 +185,8 @@ static void mwait_idle(void)
static void poll_idle(void)
- cpu_relax();
+ while (!need_resched())
+ cpu_relax();