From: Theodore Tso <tytso@mit.edu>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: Bug in delayed allocation: really bad block layouts!
Date: Tue, 12 Aug 2008 22:32:05 -0400 [thread overview]
Message-ID: <20080813023205.GA8232@mit.edu> (raw)
In-Reply-To: <20080811181524.GA9769@skywalker>
On Mon, Aug 11, 2008 at 11:45:24PM +0530, Aneesh Kumar K.V wrote:
> On Mon, Aug 11, 2008 at 08:09:12PM +0530, Aneesh Kumar K.V wrote:
> > Can you try this patch ? The patch make group preallocation use the goal
> > block.
> >
>
> Results with and without patch.
>
> http://www.radian.org/~kvaneesh/ext4/lg-fragmentation/
>
My results match yours; seems to be a bit better, but it's not fixing
the fundamental problem. With the patch:
26524: expecting 638190 actual extent phys 631960 log 1 len 1
26527: expecting 638191 actual extent phys 631963 log 1 len 1
26533: expecting 638192 actual extent phys 631976 log 1 len 5
26534: expecting 638193 actual extent phys 631981 log 1 len 2
26536: expecting 638194 actual extent phys 631984 log 1 len 6
26538: expecting 638195 actual extent phys 631991 log 1 len 5
26540: expecting 638196 actual extent phys 631997 log 1 len 2
26545: expecting 638197 actual extent phys 632009 log 1 len 1
26546: expecting 638198 actual extent phys 632010 log 1 len 6
26604: expecting 638199 actual extent phys 632156 log 1 len 1
Useing debugfs's stat command to look at the blocks:
26524: (0):638189, (1):631960
26527: (0):638190, (1):631963
26533: (0):638191, (1-5):631976-631980
26534: (0):638192, (1-2):631981-631982
26536: (0):638193, (1-6):631984-631989
26538: (0):638194, (1-5):631991-631995
26540: (0):638195, (1-2):631997-631998
26545: (0):638196, (1):632009
26546: (0):638197, (1-6):632010-632015
Out of curiosity, I also probed the inode numbers that were out of
sequence from above. They seem to be mostly allocating out of the
numbers used for the second extent, above.
26526: (0):631961
26526: (0):631962
26528: (0):631964
26529: (0):411742
26530: (0):631965
26531: (0-1):631966-631967
26532: (0-7):631968-631975
26535: (0):631983
26537: (0):631990
26541: (0-7):631999-632006
26542: (0):632007
26543: (0):632008
26544: (0):411743
26547: (0):632016
Inode Pathname
26524 /lib/rhythmbox/plugins/lyrics/LyricsConfigureDialog.py
26525 /lib/rhythmbox/plugins/lyrics/LyrcParser.py
26526 /lib/rhythmbox/plugins/lyrics/LyricsParse.py
26527 /lib/rhythmbox/plugins/lyrics/LyricsConfigureDialog.pyc
26528 /lib/rhythmbox/plugins/lyrics/WinampcnParser.py
26529 /lib/rhythmbox/plugins/magnatune
26530 /lib/rhythmbox/plugins/magnatune/magnatune_logo_color_small.png
26531 /lib/rhythmbox/plugins/magnatune/magnatune.rb-plugin
26532 /lib/rhythmbox/plugins/magnatune/magnatune-prefs.glade
26533 /lib/rhythmbox/plugins/magnatune/MagnatuneSource.pyc
26534 /lib/rhythmbox/plugins/magnatune/__init__.py
26535 /lib/rhythmbox/plugins/magnatune/BuyAlbumHandler.py
26536 /lib/rhythmbox/plugins/magnatune/magnatune-purchase.glade
26537 /lib/rhythmbox/plugins/magnatune/TrackListHandler.py
26538 /lib/rhythmbox/plugins/magnatune/MagnatuneSource.py
26539 /lib/rhythmbox/plugins/magnatune/magnatune_logo_color_tiny.png
26540 /lib/rhythmbox/plugins/magnatune/__init__.pyc
26541 /lib/rhythmbox/plugins/magnatune/magnatune-loading.glade
26542 /lib/rhythmbox/plugins/magnatune/TrackListHandler.pyc
26543 /lib/rhythmbox/plugins/magnatune/BuyAlbumHandler.pyc
26544 /lib/rhythmbox/plugins/audioscrobbler
26546 /lib/rhythmbox/plugins/audioscrobbler/audioscrobbler-prefs.glade
26547 /lib/rhythmbox/plugins/audioscrobbler/audioscrobbler-ui.xml
Looks like we still have some problems with the block allocator...
- Ted
next prev parent reply other threads:[~2008-08-13 2:32 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-10 17:30 Bug in delayed allocation: really bad block layouts! Theodore Ts'o
2008-08-10 17:54 ` Eric Sandeen
2008-08-10 18:22 ` Theodore Tso
2008-08-10 18:54 ` Eric Sandeen
2008-08-10 20:04 ` Eric Sandeen
2008-08-11 1:46 ` Theodore Tso
2008-08-11 5:36 ` Eric Sandeen
2008-08-18 10:50 ` Andreas Dilger
2008-08-10 18:28 ` Theodore Tso
2008-08-11 7:55 ` Aneesh Kumar K.V
2008-08-11 14:39 ` Aneesh Kumar K.V
2008-08-11 18:15 ` Aneesh Kumar K.V
2008-08-13 2:32 ` Theodore Tso [this message]
2008-08-13 10:52 ` Aneesh Kumar K.V
2008-08-14 21:49 ` Mingming Cao
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