From owner-cvs-all@FreeBSD.ORG  Wed Feb  6 01:02:13 2008
Return-Path: <owner-cvs-all@FreeBSD.ORG>
Delivered-To: cvs-all@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id A461F16A41A;
	Wed,  6 Feb 2008 01:02:13 +0000 (UTC)
	(envelope-from jeff@FreeBSD.org)
Received: from repoman.freebsd.org (repoman.freebsd.org
	[IPv6:2001:4f8:fff6::29])
	by mx1.freebsd.org (Postfix) with ESMTP id A143013C457;
	Wed,  6 Feb 2008 01:02:13 +0000 (UTC)
	(envelope-from jeff@FreeBSD.org)
Received: from repoman.freebsd.org (localhost [127.0.0.1])
	by repoman.freebsd.org (8.14.1/8.14.1) with ESMTP id m1612DwD041090;
	Wed, 6 Feb 2008 01:02:13 GMT (envelope-from jeff@repoman.freebsd.org)
Received: (from jeff@localhost)
	by repoman.freebsd.org (8.14.1/8.14.1/Submit) id m1612DTh041089;
	Wed, 6 Feb 2008 01:02:13 GMT (envelope-from jeff)
Message-Id: <200802060102.m1612DTh041089@repoman.freebsd.org>
From: Jeff Roberson <jeff@FreeBSD.org>
Date: Wed, 6 Feb 2008 01:02:13 +0000 (UTC)
To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org
X-FreeBSD-CVS-Branch: HEAD
Cc: 
Subject: cvs commit: src/sys/sys proc.h rwlock.h src/sys/kern kern_rwlock.c
 subr_turnstile.c
X-BeenThere: cvs-all@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: CVS commit messages for the entire tree <cvs-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-all>
List-Post: <mailto:cvs-all@freebsd.org>
List-Help: <mailto:cvs-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 06 Feb 2008 01:02:13 -0000

jeff        2008-02-06 01:02:13 UTC

  FreeBSD src repository

  Modified files:
    sys/sys              proc.h rwlock.h 
    sys/kern             kern_rwlock.c subr_turnstile.c 
  Log:
  Adaptive spinning in write path with readers and writer starvation avoidance.
   - Move recursion checking into rwlock inlines to free a bit for use with
     adaptive spinners.
   - Clear the RW_LOCK_WRITE_SPINNERS flag whenever the lock state changes
     causing write spinners to restart their loop.
   - Write spinners are limited by a count while readers hold the lock as
     there is no way to know for certain whether readers are running still.
   - In the read path block if there are write waiters or spinners to avoid
     starving writers.  Use a new per-thread count, td_rw_rlocks, to skip
     starvation avoidance if it might cause a deadlock.
   - Remove or change invalid assertions in turnstiles.
  
  Reviewed by:    attilio (developed parts of the patch as well)
  Sponsored by:   Nokia
  
  Revision  Changes    Path
  1.35      +172 -156  src/sys/kern/kern_rwlock.c
  1.171     +3 -8      src/sys/kern/subr_turnstile.c
  1.502     +2 -1      src/sys/sys/proc.h
  1.15      +6 -3      src/sys/sys/rwlock.h