Date: Mon, 29 Sep 2008 14:14:15 +0100 From: RW <fbsd06@mlists.homeunix.com> To: freebsd-hackers@freebsd.org Subject: Re: experimantal question about md's Message-ID: <20080929141415.387f931f@gumby.homeunix.com.> In-Reply-To: <1dbad3150809290136r2af024bdha9672aa0418e6cda@mail.gmail.com> References: <1dbad3150809261115h379a611aweb20e47124e254d4@mail.gmail.com> <5f67a8c40809282219w6ae93986od211c6e8c47066fe@mail.gmail.com> <1dbad3150809290136r2af024bdha9672aa0418e6cda@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 29 Sep 2008 10:36:46 +0200 "Michael Schuh" <michael.schuh@gmail.com> wrote: > so we have a webserver (par example) at this mirror it has very good > speed for the file-access > (ok i know in allmost cases is not the disk the bottleneck, and if we > could doing caching...) > at the above examle it is not really important if the write process > needs a second or two longer, > but by millions of requests it could be interseting to read the data > very fast...... That's exactly the case in which caching will work best. FreeBSD's integrated cache/VM system would keep such pages in memory even at the expense of writing other user data to swap. When I suggested a swap-backed device I was forgetting that malloc backed devices use memory that won't be paged, so there may be an advantage, but I think it would be the opposite to what you want. What it would do is keep rarely used file data in memory even if there's a better use for the memory elsewhere, so you would be trading performance for better worst-case latency.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20080929141415.387f931f>