Date: Fri, 28 Mar 2003 15:22:43 -0500 (EST) From: Jeff Roberson <jroberson@chesapeake.net> To: Daniel Eischen <eischen@pcnet1.pcnet.com> Cc: Scott Long <scott_long@btc.adaptec.com> Subject: Re: 1:1 threading. Message-ID: <20030328151526.S64602-100000@mail.chesapeake.net> In-Reply-To: <Pine.GSO.4.10.10303281352530.242-100000@pcnet1.pcnet.com>
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On Fri, 28 Mar 2003, Daniel Eischen wrote: > On Fri, 28 Mar 2003, Daniel C. Sobral wrote: > > > David Xu wrote: > > > > > > do you think that a multithreaded process should use more CPU time then > > > a single thread process, so threaded process should have higher priority > > > and block other single thread processes out? AFAIK, threading is not > > > designed for this, you may misunderstand what threading is designed for. > > > > Threading might not have been originally designed for this, but a lot of > > people use it this way, a lot of people *want* it this way, and POSIX > > specifically mandates that this way be available. > > It is available through pthread_attr_setscope(). > > There's some confusion over this and the way libthr is implemented. > KSE's within the same KSE Group were not designed to give more CPU > time than a normal unthreaded/single KSE'd process. Unless this > has been changed in the kernel somehow, the use of multiple KSEs > by libthr or libkse (in a single KSEG) will not get any more CPU > time than a non-threaded program. There was some debate over > this, but multiple KSEs within a KSEG were _not_ suppose to allow > this. You are suppose to create a new KSEG in order to get > this behavior. > This is not how it is implemented in either scheduler that we currently have. I'm not saying which way is more or less correct because I think you could argue either way. We can not entirely correctly implement SCOPE_PROCESSES threads right now anyway. This being said.. It is a property of the thr system calls and not libthr. I have a flags field in thr_create() that could be used to indicate which scope the thread should contend in. Cheers, Jeff
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