From owner-svn-src-head@freebsd.org  Sun Dec 31 02:31:02 2017
Return-Path: <owner-svn-src-head@freebsd.org>
Delivered-To: svn-src-head@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id EB7F1E82575;
 Sun, 31 Dec 2017 02:31:02 +0000 (UTC) (envelope-from mjg@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id B8DB57B81C;
 Sun, 31 Dec 2017 02:31:02 +0000 (UTC) (envelope-from mjg@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id vBV2V1rf069224;
 Sun, 31 Dec 2017 02:31:01 GMT (envelope-from mjg@FreeBSD.org)
Received: (from mjg@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id vBV2V1Jr069222;
 Sun, 31 Dec 2017 02:31:01 GMT (envelope-from mjg@FreeBSD.org)
Message-Id: <201712310231.vBV2V1Jr069222@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org
 using -f
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Sun, 31 Dec 2017 02:31:01 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r327402 - head/sys/kern
X-SVN-Group: head
X-SVN-Commit-Author: mjg
X-SVN-Commit-Paths: head/sys/kern
X-SVN-Commit-Revision: 327402
X-SVN-Commit-Repository: base
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.25
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 31 Dec 2017 02:31:03 -0000

Author: mjg
Date: Sun Dec 31 02:31:01 2017
New Revision: 327402
URL: https://svnweb.freebsd.org/changeset/base/327402

Log:
  locks: adjust loop limit check when waiting for readers
  
  The check was for the exact value, but since the counter started being
  incremented by the number of readers it could have jumped over.

Modified:
  head/sys/kern/kern_rwlock.c
  head/sys/kern/kern_sx.c

Modified: head/sys/kern/kern_rwlock.c
==============================================================================
--- head/sys/kern/kern_rwlock.c	Sun Dec 31 01:59:56 2017	(r327401)
+++ head/sys/kern/kern_rwlock.c	Sun Dec 31 02:31:01 2017	(r327402)
@@ -516,7 +516,7 @@ __rw_rlock_hard(struct rwlock *rw, struct thread *td, 
 #endif
 			KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread),
 			    "running");
-			if (i != rowner_loops)
+			if (i < rowner_loops)
 				continue;
 		}
 #endif
@@ -995,7 +995,7 @@ __rw_wlock_hard(volatile uintptr_t *c, uintptr_t v LOC
 #ifdef KDTRACE_HOOKS
 			lda.spin_cnt += rowner_loops - i;
 #endif
-			if (i != rowner_loops)
+			if (i < rowner_loops)
 				continue;
 			sleep_reason = 2;
 		}

Modified: head/sys/kern/kern_sx.c
==============================================================================
--- head/sys/kern/kern_sx.c	Sun Dec 31 01:59:56 2017	(r327401)
+++ head/sys/kern/kern_sx.c	Sun Dec 31 02:31:01 2017	(r327402)
@@ -671,7 +671,7 @@ _sx_xlock_hard(struct sx *sx, uintptr_t x, int opts LO
 #endif
 			KTR_STATE0(KTR_SCHED, "thread",
 			    sched_tdname(curthread), "running");
-			if (i != asx_loops)
+			if (i < asx_loops)
 				continue;
 			sleep_reason = 2;
 		}