Date: Thu, 27 Jul 2000 19:04:06 +0000 From: Tony Finch <dot@dotat.at> To: Mike Smith <msmith@freebsd.org> Cc: mobile@freebsd.org Subject: Re: hdd sppin-down and syncer Message-ID: <20000727190406.A426@hand.dotat.at> In-Reply-To: <200007270806.BAA42887@mass.osd.bsdi.com> References: <E13Hhru-000A7b-00@hand.dotat.at> <200007270806.BAA42887@mass.osd.bsdi.com>
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Mike Smith <msmith@freebsd.org> wrote: >> >> My Dell Latitude-CPx spins down its hdd after 10 or 15 seconds, but a >> few seconds later the syncer kicks in and it spins back up again. I >> know it might be unwise to do this but I'd like to make the syncer >> run less frequently. AFAICT one would just need to frob >> SYNCER_MAXDELAY in vfs_subr.c to acheive this, but it will go up by >> powers of two. The change below would be useful to make it easier to >> change it in a kernel configuration file. > >You should use a tunable for this... Do you mean a sysctl or something else? I realised soon after I sent the patch that I forgot to include SYSCTL_INT(_kern, OID_AUTO, syncdelay, CTLFLAG_RW, &syncdelay, 0, ""); which makes things fully tunable up to the SYSCTL_MAXDELAY setting. I'm running with it set to 256 and the sysctls are kern.syncdelay: 240 kern.filedelay: 210 kern.dirdelay: 180 kern.metadelay: 150 which seems to do what I want. I left SYNCER_MAXDELAY as a compile-time option because the syncer's work table has a fixed size and I was disinclined to make it dynamic when I ought to be going to bed. But you think that that is a reasonable thing to do and (other than keeping stuff in RAM longer than before) this won't cause trouble? Tony. -- f.a.n.finch fanf@covalent.net dot@dotat.at 427 sun-bleached stripes on the big top of banality To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message
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