From owner-freebsd-hackers Thu Apr 12 13:53:51 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id DB79937B449 for ; Thu, 12 Apr 2001 13:53:46 -0700 (PDT) (envelope-from dillon@earth.backplane.com) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.11.2) id f3CKrZ424106; Thu, 12 Apr 2001 13:53:35 -0700 (PDT) (envelope-from dillon) Date: Thu, 12 Apr 2001 13:53:35 -0700 (PDT) From: Matt Dillon Message-Id: <200104122053.f3CKrZ424106@earth.backplane.com> To: Poul-Henning Kamp Cc: Rik van Riel , David Xu , freebsd-hackers@FreeBSD.ORG Subject: Re: vm balance References: <59188.987108650@critter> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG : :In message <200104121757.f3CHvJd20639@earth.backplane.com>, Matt Dillon writes: : :> Again, keep in mind that the namei cache is strictly throw-away, but :> entries can often be reconstituted later by the filesystem without I/O :> due to the VM Page cache (and/or buffer cache depending on :> vfs.vmiodirenable). So as with the buffer cache and inode cache, :> the number of entries can be limited without killing performance or :> scaleability. : :Uhm, that is actually not true. : :We keep namecache entries around as long as we can use them, and that :generally means that recreating them is a rather expensive operation, :involving creation of vnode and very likely a vm object again. The vnode cache is a different cache. positive namei hits will reference a vnode, but namei elements can be flushed at any time without flushing the underlying vnode. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message