Re: [PATCH for-next] futex: deduplicate resched in futex_wake_op()

From: Davidlohr Bueso <dave@stgolabs.net>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Darren Hart <dvhart@infradead.org>
Subject: Re: [PATCH for-next] futex: deduplicate resched in futex_wake_op()
Date: Thu, 20 May 2021 11:16:00 -0700	[thread overview]
Message-ID: <20210520181600.oupnaspukteh7dsk@offworld> (raw)
In-Reply-To: <9b2588c1fd33c91fb01c4e348a3b647ab2c8baab.1621258128.git.asml.silence@gmail.com>

On Mon, 17 May 2021, Pavel Begunkov wrote:

>After pagefaulting in futex_wake_op() both branches do cond_resched()
>before retry. Help to deduplicate it as many compilers can't cope with
>it.
>

LGTM:

Reviewed-by: Davidlohr Bueso <dbueso@suse.de>

>Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>---
> kernel/futex.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
>diff --git a/kernel/futex.c b/kernel/futex.c
>index c98b825da9cf..54ed232b2553 100644
>--- a/kernel/futex.c
>+++ b/kernel/futex.c
>@@ -1728,12 +1728,9 @@ futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
> 				return ret;
> 		}
>
>-		if (!(flags & FLAGS_SHARED)) {
>-			cond_resched();
>-			goto retry_private;
>-		}
>-
> 		cond_resched();
>+		if (!(flags & FLAGS_SHARED))
>+			goto retry_private;
> 		goto retry;
> 	}
>
>-- 
>2.31.1
>