Date: Wed, 02 Apr 2003 15:40:16 -0800 From: Peter Wemm <peter@wemm.org> To: Terry Lambert <tlambert2@mindspring.com> Cc: current@FreeBSD.org Subject: Re: libthr and 1:1 threading. Message-ID: <20030402234016.1550D2A8A7@canning.wemm.org> In-Reply-To: <3E8B72C2.343AAEBD@mindspring.com>
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Terry Lambert wrote: > Peter Wemm wrote: > > No. It gives the ability for a thread to block on a syscall without > > stalling the entire system. Just try using mysqld on a system using libc_r > > and heavy disk IO. You can't select() on a read() from disk. Thats the > > ultimate reason to do it. The SMP parallelism is a bonus. > > Bug in FreeBSD's NBIO implementation. A read() that would result > in page-in needs to queue the request, but return EAGAIN to user > space to indicate the request cannot be satisfied. Making select() > come true for disk I/O after the fault is satisfied is a seperate > issue. Probably need to pass the fd all the way down. Umm Terry.. we have zero infrastructure to support this. Cheers, -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5
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