Date: Mon, 27 Apr 1998 09:10:43 +1000 (EST) From: John Birrell <jb@cimlogic.com.au> To: tlambert@primenet.com (Terry Lambert) Cc: hackers@FreeBSD.ORG Subject: Re: threads performance Message-ID: <199804262310.JAA14150@cimlogic.com.au> In-Reply-To: <199804262104.OAA24424@usr05.primenet.com> from Terry Lambert at "Apr 26, 98 09:04:22 pm"
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Terry Lambert wrote: > 4) Is he depending on the C++ STL? If so, he needs the one > from the Moscow Center for SPARC Computing, and he needs > some additional patches (that haven't been committed, since > STL is not widely supported in FreeBSD) to make it work > with a Draft 4 pthreads (specifically, STL assumes that you > can statically initialize mutexes, which is wrong). FWIW, -current has support for static mutexes (draft 10). To fix the performance problem that people are seeing, I'll fix the signal handling to use a single set of sigactions for the process (as POSIX says) and dispatch signals immediately without using a thread as the signal handler (this was a bad idea from the beginning, but it was coded before the standard was released). This will mean that a signal handler won't need to call any functions which require locks, so these can be changed to simple spinlocks (with sched_yield) instead of using the (kernel) sigmask to make things atomic. It is the repeated calls to change (or check) the sigmask that are the killer as far as I can tell, but it depends on what the application is doing as to whether they get noticed. -- John Birrell - jb@cimlogic.com.au; jb@freebsd.org http://www.cimlogic.com.au/ CIMlogic Pty Ltd, GPO Box 117A, Melbourne Vic 3001, Australia +61 418 353 137 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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