On Tue, 15 Jan 2002, David Wolfskill wrote: > >Date: Tue, 15 Jan 2002 16:46:17 -0800 (PST) > >From: John Baldwin <[EMAIL PROTECTED]> > >Two questions: > > >1) Do you have WITNESS on in your kernel config? > > Yes, in both the build machine & the laptop -- since before I made a > "local" hierarchy within my CVS repository (September 9, 2001). > > >2) If yes, have you tried building with a kernel without witness? > > No, not since I put it in to re-sync with GENERIC. I could try that, I > suppose -- but as noted, I've had WITNESS in there for a while; something > seems to have changed during that one 24-hr. period that affected things > rather radically. And I thought it notable. :-} > > I gather no one else has noticed this?
File locking seems to cause only the usual few percent of slowdown for each round of major locking changes. I haven't completed benchmarking the file locking pessimizations. I don't use WITNESS or INVARIANTS for benchmarking of course. Maybe the file locking changes cause much larger pessimizations when WITNESS is turned on than most locking changes. I can see how they might: WITNESS seemed to slow down creation and destruction of mutexes more than most mutex operations last time I checked, and there is a descriptor for each file and each file descriptor. Bruce To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
