From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20106 invoked by alias); 30 Mar 2011 13:14:37 -0000 Received: (qmail 20087 invoked by uid 9737); 30 Mar 2011 13:14:36 -0000 Date: Wed, 30 Mar 2011 13:14:00 -0000 Message-ID: <20110330131436.20085.qmail@sourceware.org> From: zkabelac@sourceware.org To: lvm-devel@redhat.com, lvm2-cvs@sourceware.org Subject: LVM2 ./WHATS_NEW lib/cache/lvmcache.c lib/cach ... Mailing-List: contact lvm2-cvs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: lvm2-cvs-owner@sourceware.org X-SW-Source: 2011-03/txt/msg00098.txt.bz2 CVSROOT: /cvs/lvm2 Module name: LVM2 Changes by: zkabelac@sourceware.org 2011-03-30 13:14:34 Modified files: . : WHATS_NEW lib/cache : lvmcache.c lvmcache.h Log message: Keep the cache content when the exported vg buffer is matching Instead of regenerating config tree and parsing same data again, check whether export_vg_to_buffer does not produce same string as the one already cached - in this case keep it, otherwise throw cached content away. For the code simplicity calling _free_cached_vgmetadata() with vgmetadata == NULL as the function handles this itself. Note: sometimes export_vg_to_buffer() generates almost the same data with just different time stamp, but for the patch simplicity, data are reparsed in this case. This patch currently helps for vgrefresh. Patches: http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.1966&r2=1.1967 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/cache/lvmcache.c.diff?cvsroot=lvm2&r1=1.108&r2=1.109 http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/lib/cache/lvmcache.h.diff?cvsroot=lvm2&r1=1.37&r2=1.38 --- LVM2/WHATS_NEW 2011/03/30 13:06:13 1.1966 +++ LVM2/WHATS_NEW 2011/03/30 13:14:34 1.1967 @@ -1,5 +1,6 @@ Version 2.02.85 - =================================== + Keep the cache content when the exported vg buffer is matching. Extend the set of memory regions, that are not locked to memory. Enhance usability with the valgrind memcheck tool. Support regular quit of the lvm_thread_fn function in clvmd. --- LVM2/lib/cache/lvmcache.c 2011/03/29 21:34:18 1.108 +++ LVM2/lib/cache/lvmcache.c 2011/03/30 13:14:34 1.109 @@ -99,6 +99,7 @@ { char uuid[64] __attribute__((aligned(8))); struct lvmcache_vginfo *vginfo; + char *data; int size; if (!(vginfo = vginfo_from_vgid((const char *)&vg->id))) { @@ -106,14 +107,22 @@ return; } - if (vginfo->vgmetadata) - _free_cached_vgmetadata(vginfo); - - if (!(size = export_vg_to_buffer(vg, &vginfo->vgmetadata))) { + if (!(size = export_vg_to_buffer(vg, &data))) { stack; + _free_cached_vgmetadata(vginfo); return; } + /* Avoid reparsing of the same data string */ + if (vginfo->vgmetadata && vginfo->vgmetadata_size == size && + strcmp(vginfo->vgmetadata, data) == 0) + dm_free(data); + else { + _free_cached_vgmetadata(vginfo); + vginfo->vgmetadata_size = size; + vginfo->vgmetadata = data; + } + vginfo->precommitted = precommitted; if (!id_write_format((const struct id *)vginfo->vgid, uuid, sizeof(uuid))) { --- LVM2/lib/cache/lvmcache.h 2011/01/10 13:15:57 1.37 +++ LVM2/lib/cache/lvmcache.h 2011/03/30 13:14:34 1.38 @@ -46,6 +46,7 @@ char _padding[7]; struct lvmcache_vginfo *next; /* Another VG with same name? */ char *creation_host; + size_t vgmetadata_size; char *vgmetadata; /* Copy of VG metadata as format_text string */ struct config_tree *cft; /* Config tree created from vgmetadata */ /* Lifetime is directly tied to vgmetadata */