[PATCH v2] generic-ipi: kill unnecessary variable - csd_flags

[PATCH v2] generic-ipi: kill unnecessary variable - csd_flags

[Xie XiuQi]

After commit:8969a5ede0f9e17da4b943712429aef2c9bcd82b
"generic-ipi: remove kmalloc()", wait = 0 can be guaranteed.

And all callsites of generic_exec_single() do an unconditional
csd_lock() now.

So csd_flags is unnecessary now. Remote it.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patchwork.kernel.org/patch/2834744/
---
 kernel/smp.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index fe9f773..7332697 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -186,25 +186,13 @@ void generic_smp_call_function_single_interrupt(void)

 	while (!list_empty(&list)) {
 		struct call_single_data *csd;
-		unsigned int csd_flags;

 		csd = list_entry(list.next, struct call_single_data, list);
 		list_del(&csd->list);

-		/*
-		 * 'csd' can be invalid after this call if flags == 0
-		 * (when called through generic_exec_single()),
-		 * so save them away before making the call:
-		 */
-		csd_flags = csd->flags;
-
 		csd->func(csd->info);

-		/*
-		 * Unlocked CSDs are valid through generic_exec_single():
-		 */
-		if (csd_flags & CSD_FLAG_LOCK)
-			csd_unlock(csd);
+		csd_unlock(csd);
 	}
 }

-- 
1.8.2.1

Re: [PATCH v2] generic-ipi: kill unnecessary variable - csd_flags

[Peter Zijlstra]

On Tue, Jul 30, 2013 at 11:06:09AM +0800, Xie XiuQi wrote:
> After commit:8969a5ede0f9e17da4b943712429aef2c9bcd82b
> "generic-ipi: remove kmalloc()", wait = 0 can be guaranteed.
> 
> And all callsites of generic_exec_single() do an unconditional
> csd_lock() now.
> 
> So csd_flags is unnecessary now. Remote it.
> 
> Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Link: https://patchwork.kernel.org/patch/2834744/

Thanks!

[tip:sched/core] generic-ipi: Kill unnecessary variable - csd_flags

[tip-bot for Xie XiuQi]

Commit-ID:  46591962cb5bfd2bfb0baf42497119c816503598
Gitweb:     http://git.kernel.org/tip/46591962cb5bfd2bfb0baf42497119c816503598
Author:     Xie XiuQi <xiexiuqi@huawei.com>
AuthorDate: Tue, 30 Jul 2013 11:06:09 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 30 Jul 2013 22:19:05 +0200

generic-ipi: Kill unnecessary variable - csd_flags

After commit 8969a5ede0f9e17da4b943712429aef2c9bcd82b
("generic-ipi: remove kmalloc()"), wait = 0 can be guaranteed,
and all callsites of generic_exec_single() do an unconditional
csd_lock() now.

So csd_flags is unnecessary now. Remove it.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/r/51F72DA1.7010401@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/smp.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index fe9f773..7332697 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -186,25 +186,13 @@ void generic_smp_call_function_single_interrupt(void)
 
 	while (!list_empty(&list)) {
 		struct call_single_data *csd;
-		unsigned int csd_flags;
 
 		csd = list_entry(list.next, struct call_single_data, list);
 		list_del(&csd->list);
 
-		/*
-		 * 'csd' can be invalid after this call if flags == 0
-		 * (when called through generic_exec_single()),
-		 * so save them away before making the call:
-		 */
-		csd_flags = csd->flags;
-
 		csd->func(csd->info);
 
-		/*
-		 * Unlocked CSDs are valid through generic_exec_single():
-		 */
-		if (csd_flags & CSD_FLAG_LOCK)
-			csd_unlock(csd);
+		csd_unlock(csd);
 	}
 }