Subject: + kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask.patch added to -mm tree
To: david.daney@xxxxxxxxxx,a.p.zijlstra@xxxxxxxxx,cl@xxxxxxxxx,cmetcalf@xxxxxxxxxx,gilad@xxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 12 Aug 2013 15:16:38 -0700
The patch titled
Subject: kernel/smp.c: quit unconditionally enabling irqs in on_each_cpu_mask().
has been added to the -mm tree. Its filename is
kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: David Daney <david.daney@xxxxxxxxxx>
Subject: kernel/smp.c: quit unconditionally enabling irqs in on_each_cpu_mask().
As in f21afc25f9ed ("smp.h: Use local_irq_{save,restore}() in !SMP version
of on_each_cpu()"), we don't want to enable irqs if they are not already
enabled.
I don't know of any bugs currently caused by this unconditional
local_irq_enable(), but I want to use this function in MIPS/OCTEON early
boot (when we have early_boot_irqs_disabled). This also makes this
function have similar semantics to on_each_cpu() which is good in itself.
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Cc: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/smp.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff -puN kernel/smp.c~kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask kernel/smp.c
--- a/kernel/smp.c~kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask
+++ a/kernel/smp.c
@@ -575,8 +575,10 @@ EXPORT_SYMBOL(on_each_cpu);
*
* If @wait is true, then returns once @func has returned.
*
- * You must not call this function with disabled interrupts or
- * from a hardware interrupt handler or from a bottom half handler.
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler. The
+ * exception is that it may be used during early boot while
+ * early_boot_irqs_disabled is set.
*/
void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
void *info, bool wait)
@@ -585,9 +587,10 @@ void on_each_cpu_mask(const struct cpuma
smp_call_function_many(mask, func, info, wait);
if (cpumask_test_cpu(cpu, mask)) {
- local_irq_disable();
+ unsigned long flags;
+ local_irq_save(flags);
func(info);
- local_irq_enable();
+ local_irq_restore(flags);
}
put_cpu();
}
_
Patches currently in -mm which might be from david.daney@xxxxxxxxxx are
linux-next.patch
revert-include-linux-smph-on_each_cpu-switch-back-to-a-macro.patch
smp-quit-unconditionally-enabling-irq-in-on_each_cpu_mask-and-on_each_cpu_cond.patch
upc-use-local_irq_saverestore-in-smp_call_function_single.patch
smph-move-smp-version-of-on_each_cpu-out-of-line.patch
extable-skip-sorting-if-the-table-is-empty.patch
kernel-smpc-quit-unconditionally-enabling-irqs-in-on_each_cpu_mask.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
