[lvm-devel] [PATCH 0/3] Share vg metadata for read only
Zdenek Kabelac
zkabelac at redhat.com
Wed Feb 23 13:52:14 UTC 2011
Another nice speedup:
1st. patch refactors allocation of VG to one place - so refcounting
is simplier to implement (I'm planning few more cleanup patches for
this)
2nd. patch adds reference counting and caching of VG struct
As Milan suggested - I'll try to add extra code which will try to
check checksum of memory pool used for VG (with DEBUG_MEM option probably)
Some numbers with ~1700 volumes and current default rawhide kernel:
2.6.38-0.rc5.git1.1.fc15.x86_64
lvm2-2.02.84-1.fc15.x86_64
(killed gvfs... and removed udisk udev rules
- as these are currently major performance killers)
vgchange -ay
real 0m50.097s
user 0m10.765s
sys 0m35.481s
vgchange -ay (here are LVs already actived)
real 0m10.425s
user 0m8.240s
sys 0m2.133s
vgchange -an
real 0m51.339s
user 0m10.375s
sys 0m31.457s
vgchange -an (here are LVs already deactived)
real 0m10.288s
user 0m8.328s
sys 0m1.901s
and now the same with new lvm2 sharing code (and critical section)
vgchange -ay
real 0m13.792s (udev is slowing it down by 3 seconds)
user 0m0.629s
sys 0m4.535s
vgchange -ay
real 0m0.745s
user 0m0.170s
sys 0m0.520s
vgchange -an
real 0m9.886s
user 0m0.425s
sys 0m2.418s
vgchange -an
real 0m0.468s
user 0m0.158s
sys 0m0.239s
Zdenek Kabelac (3):
Refactor vg allocation code
Add VG refcount and cache created VG structure
Destroy 'fic' memory in error path
lib/cache/lvmcache.c | 55 +++++++++++++++++++++++++++-------------
lib/cache/lvmcache.h | 4 ++-
lib/format_text/import_vsn1.c | 33 +++++++-----------------
lib/metadata/metadata.c | 40 ++++++-----------------------
lib/metadata/vg.c | 26 +++++++++++++++++++
lib/metadata/vg.h | 3 ++
6 files changed, 88 insertions(+), 73 deletions(-)
--
1.7.4.1
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