Date: Wed, 4 Dec 2013 07:38:24 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r258909 - in head: sbin/mdconfig sys/dev/md sys/sys Message-ID: <201312040738.rB47cOsV009261@svn.freebsd.org>
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Author: trasz Date: Wed Dec 4 07:38:23 2013 New Revision: 258909 URL: http://svnweb.freebsd.org/changeset/base/258909 Log: Add "null" backend to mdconfig(8). This does exactly what the name suggests, and is somewhat useful for benchmarking. MFC after: 1 month No objections from: kib Sponsored by: The FreeBSD Foundation Modified: head/sbin/mdconfig/mdconfig.8 head/sbin/mdconfig/mdconfig.c head/sys/dev/md/md.c head/sys/sys/mdioctl.h Modified: head/sbin/mdconfig/mdconfig.8 ============================================================================== --- head/sbin/mdconfig/mdconfig.8 Wed Dec 4 05:06:56 2013 (r258908) +++ head/sbin/mdconfig/mdconfig.8 Wed Dec 4 07:38:23 2013 (r258909) @@ -41,7 +41,7 @@ .\" .\" $FreeBSD$ .\" -.Dd October 26, 2013 +.Dd November 30, 2013 .Dt MDCONFIG 8 .Os .Sh NAME @@ -122,6 +122,8 @@ Using backing is generally preferred instead of using .Cm malloc backing. +.It Cm null +Bitsink; all writes do nothing, all reads return zeroes. .El .It Fl f Ar file Filename to use for the vnode type memory disk. Modified: head/sbin/mdconfig/mdconfig.c ============================================================================== --- head/sbin/mdconfig/mdconfig.c Wed Dec 4 05:06:56 2013 (r258908) +++ head/sbin/mdconfig/mdconfig.c Wed Dec 4 07:38:23 2013 (r258909) @@ -155,6 +155,9 @@ main(int argc, char **argv) } else if (!strcmp(optarg, "swap")) { mdio.md_type = MD_SWAP; mdio.md_options |= MD_CLUSTER | MD_AUTOUNIT | MD_COMPRESS; + } else if (!strcmp(optarg, "null")) { + mdio.md_type = MD_NULL; + mdio.md_options |= MD_CLUSTER | MD_AUTOUNIT | MD_COMPRESS; } else errx(1, "unknown type: %s", optarg); break; @@ -287,9 +290,10 @@ main(int argc, char **argv) } } - if ((mdio.md_type == MD_MALLOC || mdio.md_type == MD_SWAP) && - sflag == NULL) - errx(1, "must specify -s for -t malloc or -t swap"); + if ((mdio.md_type == MD_MALLOC || mdio.md_type == MD_SWAP || + mdio.md_type == MD_NULL) && sflag == NULL) + errx(1, "must specify -s for -t malloc, -t swap, " + "or -t null"); if (mdio.md_type == MD_VNODE && mdio.md_file[0] == '\0') errx(1, "must specify -f for -t vnode"); } else { Modified: head/sys/dev/md/md.c ============================================================================== --- head/sys/dev/md/md.c Wed Dec 4 05:06:56 2013 (r258908) +++ head/sys/dev/md/md.c Wed Dec 4 07:38:23 2013 (r258909) @@ -908,6 +908,22 @@ mdstart_swap(struct md_s *sc, struct bio return (rv != VM_PAGER_ERROR ? 0 : ENOSPC); } +static int +mdstart_null(struct md_s *sc, struct bio *bp) +{ + + switch (bp->bio_cmd) { + case BIO_READ: + bzero(bp->bio_data, bp->bio_length); + cpu_flush_dcache(bp->bio_data, bp->bio_length); + break; + case BIO_WRITE: + break; + } + bp->bio_resid = 0; + return (0); +} + static void md_kthread(void *arg) { @@ -1027,6 +1043,7 @@ mdinit(struct md_s *sc) pp->flags |= G_PF_ACCEPT_UNMAPPED; break; case MD_PRELOAD: + case MD_NULL: break; } sc->gp = gp; @@ -1245,6 +1262,7 @@ mdresize(struct md_s *sc, struct md_ioct switch (sc->type) { case MD_VNODE: + case MD_NULL: break; case MD_SWAP: if (mdio->md_mediasize <= 0 || @@ -1339,6 +1357,19 @@ mdcreate_swap(struct md_s *sc, struct md return (error); } +static int +mdcreate_null(struct md_s *sc, struct md_ioctl *mdio, struct thread *td) +{ + + /* + * Range check. Disallow negative sizes or any size less then the + * size of a page. Then round to a page. + */ + if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0) + return (EDOM); + + return (0); +} static int xmdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td) @@ -1371,6 +1402,7 @@ xmdctlioctl(struct cdev *dev, u_long cmd case MD_PRELOAD: case MD_VNODE: case MD_SWAP: + case MD_NULL: break; default: return (EINVAL); @@ -1416,6 +1448,10 @@ xmdctlioctl(struct cdev *dev, u_long cmd sc->start = mdstart_swap; error = mdcreate_swap(sc, mdio, td); break; + case MD_NULL: + sc->start = mdstart_null; + error = mdcreate_null(sc, mdio, td); + break; } if (error != 0) { mddestroy(sc, td); @@ -1586,6 +1622,9 @@ g_md_dumpconf(struct sbuf *sb, const cha case MD_SWAP: type = "swap"; break; + case MD_NULL: + type = "null"; + break; default: type = "unknown"; break; Modified: head/sys/sys/mdioctl.h ============================================================================== --- head/sys/sys/mdioctl.h Wed Dec 4 05:06:56 2013 (r258908) +++ head/sys/sys/mdioctl.h Wed Dec 4 07:38:23 2013 (r258909) @@ -43,7 +43,7 @@ #ifndef _SYS_MDIOCTL_H_ #define _SYS_MDIOCTL_H_ -enum md_types {MD_MALLOC, MD_PRELOAD, MD_VNODE, MD_SWAP}; +enum md_types {MD_MALLOC, MD_PRELOAD, MD_VNODE, MD_SWAP, MD_NULL}; /* * Ioctl definitions for memory disk pseudo-device.
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