Date: Wed, 20 Feb 2002 17:27:36 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Alfred Perlstein <alfred@FreeBSD.org> Cc: cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: RE: cvs commit: src/sys/i386/conf GENERIC Message-ID: <XFMail.020220172736.jhb@FreeBSD.org> In-Reply-To: <200202131847.g1DIlp851160@freefall.freebsd.org>
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On 13-Feb-02 Alfred Perlstein wrote: > alfred 2002/02/13 10:47:51 PST > > Modified files: > sys/i386/conf GENERIC > Log: > Re-enable WITNESS for GENERIC. Since the 5.x branch is mostly about > SMP we'd like as much feedback as possible from users about possible > locking problems as early as possible. > > To negate most of the performance impact I've also enabled > WITNESS_SKIPSPIN. I've done this as we've been running WITNESS > over the spinlock code for a while without incident and it goes a > long way to making the performance problems of WITNESS much more > bearable. Actually, there are problems with teh clock lock and sched lock on alpha. :) > Users who should be running current should know about turning WITNESS > off for performance reasons. > > That said and done, WITNESS could/should be made into a tuneable, > but we'll leave that as an excersize to those that want to disable > it without a kernel recompile. set debug.witness_watch=0 WITNESS_SKIPSPIN is also a tunable and is documented as such in witness(4). debug.witness_watch isn't documented in witness(4) but should be. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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