* Dont use shortcut when using send_IPI_all in flat mode
@ 2005-09-21 20:52 Ashok Raj
2005-09-22 9:44 ` Andi Kleen
0 siblings, 1 reply; 2+ messages in thread
From: Ashok Raj @ 2005-09-21 20:52 UTC (permalink / raw)
To: linux-kernel; +Cc: akpm, ak, discuss
Hi
This got missed during the previous update for not doing shortcut
since it introduces race in IPI, when using flat mode.
The earlier patches addressed send_IPI_allbutself, this one
take care of the sendall() case as well.
Andrew: Please consider for -mm
--
Cheers,
Ashok Raj
- Open Source Technology Center
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
--------------------------------------------------------
arch/x86_64/kernel/genapic_flat.c | 4 ++++
1 files changed, 4 insertions(+)
Index: linux-2.6.14-rc1-mm1/arch/x86_64/kernel/genapic_flat.c
===================================================================
--- linux-2.6.14-rc1-mm1.orig/arch/x86_64/kernel/genapic_flat.c
+++ linux-2.6.14-rc1-mm1/arch/x86_64/kernel/genapic_flat.c
@@ -94,7 +94,11 @@ static void flat_send_IPI_allbutself(int
static void flat_send_IPI_all(int vector)
{
+#ifndef CONFIG_HOTPLUG_CPU
__send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
+#else
+ flat_send_IPI_mask(cpu_online_map, vector);
+#endif
}
static int flat_apic_id_registered(void)
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Dont use shortcut when using send_IPI_all in flat mode
2005-09-21 20:52 Dont use shortcut when using send_IPI_all in flat mode Ashok Raj
@ 2005-09-22 9:44 ` Andi Kleen
0 siblings, 0 replies; 2+ messages in thread
From: Andi Kleen @ 2005-09-22 9:44 UTC (permalink / raw)
To: Ashok Raj; +Cc: linux-kernel, akpm, discuss
On Wed, Sep 21, 2005 at 01:52:16PM -0700, Ashok Raj wrote:
> Hi
>
> This got missed during the previous update for not doing shortcut
> since it introduces race in IPI, when using flat mode.
>
> The earlier patches addressed send_IPI_allbutself, this one
> take care of the sendall() case as well.
>
> Andrew: Please consider for -mm
It's not needed because genapic always sets physflat when
CONFIG_HOTPLUG_CPU is set.
In fact the other HOTPLUG_CPU ifdefs in genapic_flat you added
can be removed now.
-Andi
^ permalink raw reply [flat|nested] 2+ messages in thread
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