Date: Wed, 5 Nov 2003 04:40:23 -0500 (EST) From: Jeff Roberson <jroberson@chesapeake.net> To: David Xu <davidxu@viatech.com.cn> Cc: current@freebsd.org Subject: Re: SYSENTER in FreeBSD Message-ID: <20031105043821.A10222-100000@mail.chesapeake.net> In-Reply-To: <3FA8BD16.2080705@viatech.com.cn>
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On Wed, 5 Nov 2003, David Xu wrote: > Jun Su wrote: > > >I noticed that Jeff Roberson implement this already. Is whi will be commit? > >http://kerneltrap.org/node/view/1531 > > > >I google this because I found this feature is listed in the list of Kernel Improvement of WindowsXP. :-) > > > >Thanks, > >Jun Su > > > > > > > I have almost done this experiment about 10 months ago. > http://people.freebsd.org/~davidxu/fastsyscall/ > The patch is out of date and still not complete. > Also it can give you some performance improve, but I think too many > things need to be changed, > and this really makes user ret code very dirty, some syscalls, for > example, pipe() can not use > this fast syscall, becaues pipe() seems using two registers to return > file handle, the performance gain > is immediately lost when the assemble code becomes more complex. I don't > think this hack is worth > to do on IA32, I heard AMD has different way to support fast syscall, > that may already in FreeBSD > AMD 64 branch. This works with every syscall. I have a patch in perforce that doesn't require any changes to userret(). The performance gain is not so substantial for most things but I feel that it is worth it. Mini is probably going to finish this up over the next week or so. Cheers, Jeff > > David Xu > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >
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