From: Shaohua Li <shaohua.li@intel.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: "Raj, Ashok" <ashok.raj@intel.com>, akpm <akpm@osdl.org>, ak <ak@muc.de>
Subject: trival patch: disable interrupt in play_dead
Date: Mon, 28 Nov 2005 22:48:16 -0800 [thread overview]
Message-ID: <1133246896.8076.4.camel@linux.site> (raw)
It's physical CPU hotplug now, so disable interrupt in play_dead.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
linux-2.6.14-root/arch/x86_64/kernel/process.c | 5 +++--
linux-2.6.14-root/include/asm-x86_64/system.h | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff -puN arch/x86_64/kernel/process.c~cpuhp-disable-interrupt arch/x86_64/kernel/process.c
--- linux-2.6.14/arch/x86_64/kernel/process.c~cpuhp-disable-interrupt 2005-11-28 22:20:28.000000000 -0800
+++ linux-2.6.14-root/arch/x86_64/kernel/process.c 2005-11-28 22:20:28.000000000 -0800
@@ -157,7 +157,7 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
DECLARE_PER_CPU(int, cpu_state);
#include <asm/nmi.h>
-/* We don't actually take CPU down, just spin without interrupts. */
+/* We halt the CPU with physical CPU hotplug */
static inline void play_dead(void)
{
idle_task_exit();
@@ -166,8 +166,9 @@ static inline void play_dead(void)
/* Ack it */
__get_cpu_var(cpu_state) = CPU_DEAD;
+ local_irq_disable();
while (1)
- safe_halt();
+ halt();
}
#else
static inline void play_dead(void)
diff -puN include/asm-x86_64/system.h~cpuhp-disable-interrupt include/asm-x86_64/system.h
--- linux-2.6.14/include/asm-x86_64/system.h~cpuhp-disable-interrupt 2005-11-28 22:20:28.000000000 -0800
+++ linux-2.6.14-root/include/asm-x86_64/system.h 2005-11-28 22:20:28.000000000 -0800
@@ -315,6 +315,8 @@ static inline unsigned long __cmpxchg(vo
#define local_irq_enable() __asm__ __volatile__("sti": : :"memory")
/* used in the idle loop; sti takes one instruction cycle to complete */
#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory")
+/* used when interrupts are already enabled or to shutdown the processor */
+#define halt() __asm__ __volatile__("hlt": : :"memory")
#define irqs_disabled() \
({ \
_
reply other threads:[~2005-11-28 23:27 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1133246896.8076.4.camel@linux.site \
--to=shaohua.li@intel.com \
--cc=ak@muc.de \
--cc=akpm@osdl.org \
--cc=ashok.raj@intel.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox