Date: Fri, 1 May 1998 09:39:37 -0700 (PDT) From: Julian Elischer <julian@whistle.com> To: Bruce Evans <bde@freebsd.org> Cc: cvs-committers@freebsd.org, cvs-all@freebsd.org, cvs-sys@freebsd.org Subject: Re: cvs commit: src/sys/kern vfs_cluster.c Message-ID: <Pine.BSF.3.95.980501093134.1869G-100000@current1.whistle.com> In-Reply-To: <199805011629.JAA15097@freefall.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Talking of clusterring.. One problem with clustering is the fact that the flag that dissallows CLUSTERING is stored in the BDEVSW entry. from sys/conf.h: #define D_NOCLUSTERR 0x10000 /* disables cluter read */ #define D_NOCLUSTERW 0x20000 /* disables cluster write */ #define D_NOCLUSTERRW (D_NOCLUSTERR | D_NOCLUSTERW) which is patently the wrong place for it. for several reasons: 1/ different SCSI devices may have different ideas about clustering.. 2/ in DEVFS/SLICE, all disks come in through the same major number/devfs[] entry no matter which driver they eventually get passed to. 3/ [bc]devsw entries will totally go away anyhow. On Fri, 1 May 1998, Bruce Evans wrote: > Log: > Partially fixed write clustering for cases where cluster_wbuild() is > called from vfs_bio_awrite() without going through cluster_write() > or ufs_bmaparray(), in particular for all writes to block disk devices. > Only ufs_bmaparray() sets vp->v_maxio in a correct way, and it doesn't > seem to be called early enough even for regular files.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.95.980501093134.1869G-100000>