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From: Ulrich Drepper <drepper@redhat.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@osdl.org>
Subject: [PATCH] Simplify last lib/idr.c change
Date: Wed, 22 Sep 2004 23:06:28 -0700	[thread overview]
Message-ID: <415267E4.4080302@redhat.com> (raw)

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The last change to alloc_layer in lib/idr.c unnecessarily complicates
the code and depending on the definition of spin_unlock will cause worse
code to be generated than necessary.  The following patch should improve
the situation.


Signed-off-by: Ulrich Drepper <drepper@redhat.com>

- --- lib/idr.c-old	2004-09-22 23:02:15.000000000 -0700
+++ lib/idr.c	2004-09-22 23:03:06.000000000 -0700
@@ -39,13 +39,11 @@ static struct idr_layer *alloc_layer(str
 	struct idr_layer *p;

 	spin_lock(&idp->lock);
- -	if (!(p = idp->id_free)) {
- -		spin_unlock(&idp->lock);
- -		return NULL;
+	if ((p = idp->id_free)) {
+		idp->id_free = p->ary[0];
+		idp->id_free_cnt--;
+		p->ary[0] = NULL;
 	}
- -	idp->id_free = p->ary[0];
- -	idp->id_free_cnt--;
- -	p->ary[0] = NULL;
 	spin_unlock(&idp->lock);
 	return(p);
 }


- --
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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                 reply	other threads:[~2004-09-23  6:07 UTC|newest]

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