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Date: Tue, 13 Sep 2016 01:14:41 -0700
From: Davidlohr Bueso <dave@stgolabs.net>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 1/5] ipc/sem: do not call wake_sem_queue_do() prematurely
Message-ID: <20160913081441.GA32365@linux-80c1.suse>
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On Tue, 13 Sep 2016, Manfred Spraul wrote:

>>-	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
>>-		goto out_rcu_wakeup;
>>+	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {
>>+		rcu_read_unlock();
>>+		goto out_free;
>>+	}
>Is this really better/simpler?
>You replace "if (error) goto cleanup" with "if (error) {cleanup_1(); 
>goto cleanup_2()}".

I believe it is better as it clearly separates blocking from non-blocking
exit paths. Overhead of course is irrelevant in both in-house wake_up_sem_queue_do
and wake_up_q.

Thanks,
Davidlohr