Date: Mon, 10 Oct 2005 13:01:50 +0200 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Peter Edwards <peadar.edwards@gmail.com> Cc: src-committers@freebsd.org, Pawel Jakub Dawidek <pjd@freebsd.org>, Peter Edwards <peadar@freebsd.org>, cvs-src@freebsd.org, cvs-all@freebsd.org, S?ren Schmidt <sos@freebsd.org> Subject: Re: cvs commit: src/sys/dev/ata atapi-cd.c Message-ID: <13986.1128942110@critter.freebsd.dk> In-Reply-To: Your message of "Mon, 10 Oct 2005 11:56:34 BST." <34cb7c840510100356t1b93e679v6479afda16277afa@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <34cb7c840510100356t1b93e679v6479afda16277afa@mail.gmail.com>, Peter Edwards writes: >> +> Please see geom_disk.c >> >I think an advantage to Poul-Henning's approach is that it reduces >latency: the I/O can start immediately, rather than requiring all the >bio's to be allocated first. The very fact that the race condition was >triggered indicates that the IO devices can overtake the CPU. You >might waste some time in the failure case, but that's obviously a >small price to pay for improved performance in the normal run of >things. Agreed. I've started wondering if I should actually put this code in a function so we don't have to reinvent it all over the place. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?13986.1128942110>