From: James Bottomley <James.Bottomley@SteelEye.com>
To: 'Dave Olien' <dmo@osdl.org>, Jens Axboe <axboe@suse.de>
Cc: "Qi, Yanling" <yanling.qi@engenio.com>,
Douglas Gilbert <dougg@torque.net>,
Tim Pepper <tpepper@gmail.com>,
SCSI Mailing List <linux-scsi@vger.kernel.org>
Subject: Re: Question about Request Sense case in scsi_lib.c
Date: 14 Oct 2004 15:39:29 -0500 [thread overview]
Message-ID: <1097786376.2198.43.camel@mulgrave> (raw)
In-Reply-To: <20041014175218.GA31885@osdl.org>
OK, I caught it with actual data this time
If you analyse my trace you see that blk_rq_map_sg() is insisting on a
phys segment size of no more than 65536 bytes (which gives it 11
segments since some are bigger than this). However, an exact count of
the number of phys segments without this boundary would yield 5, which
is exactly the figure we get.
I theorise that the initial request had nr_phys_segments pretty high, so
it mapped OK. Then later we trigger a recount somehow using
blk_recalc_rq_segments() which drops it to 5
Therefore it seems to me that the problem occurs because
blk_recalc_rq_segment size is failing to respect the queueu
max_segment_size (which is set to 65536 by default).
James
REQUEUE: doing a reinsertion of request c37dc270, use_sg=11, nr_phys_segments=5, nr_hw_segments=128
FOUND FAILING CASE
after recalc_rq_segments nr_phys_segments=5, nr_hw_segments=128
SG SEGMENTS FROM cmd ARE:
0: 0x008e7000-0x008f7000 [65536]
1: 0x008f7000-0x00903000 [49152]
2: 0x00904000-0x00914000 [65536]
3: 0x00914000-0x00919000 [20480]
4: 0x0091a000-0x0091e000 [16384]
5: 0x0091f000-0x0092f000 [65536]
6: 0x0092f000-0x0093f000 [65536]
7: 0x0093f000-0x0094f000 [65536]
8: 0x0094f000-0x00958000 [36864]
9: 0x00959000-0x00969000 [65536]
10: 0x00969000-0x0096b000 [8192]
bio0, seg0: 0x008e7000-0x008e8000 [4096]
bio1, seg0: 0x008e8000-0x008e9000 [4096]
bio2, seg0: 0x008e9000-0x008ea000 [4096]
bio3, seg0: 0x008ea000-0x008eb000 [4096]
bio4, seg0: 0x008eb000-0x008ec000 [4096]
bio5, seg0: 0x008ec000-0x008ed000 [4096]
bio6, seg0: 0x008ed000-0x008ee000 [4096]
bio7, seg0: 0x008ee000-0x008ef000 [4096]
bio8, seg0: 0x008ef000-0x008f0000 [4096]
bio9, seg0: 0x008f0000-0x008f1000 [4096]
bio10, seg0: 0x008f1000-0x008f2000 [4096]
bio11, seg0: 0x008f2000-0x008f3000 [4096]
bio12, seg0: 0x008f3000-0x008f4000 [4096]
bio13, seg0: 0x008f4000-0x008f5000 [4096]
bio14, seg0: 0x008f5000-0x008f6000 [4096]
bio15, seg0: 0x008f6000-0x008f7000 [4096]
bio16, seg0: 0x008f7000-0x008f8000 [4096]
bio17, seg0: 0x008f8000-0x008f9000 [4096]
bio18, seg0: 0x008f9000-0x008fa000 [4096]
bio19, seg0: 0x008fa000-0x008fb000 [4096]
bio20, seg0: 0x008fb000-0x008fc000 [4096]
bio21, seg0: 0x008fc000-0x008fd000 [4096]
bio22, seg0: 0x008fd000-0x008fe000 [4096]
bio23, seg0: 0x008fe000-0x008ff000 [4096]
bio24, seg0: 0x008ff000-0x00900000 [4096]
bio25, seg0: 0x00900000-0x00901000 [4096]
bio26, seg0: 0x00901000-0x00902000 [4096]
bio27, seg0: 0x00902000-0x00903000 [4096]
bio28, seg0: 0x00904000-0x00905000 [4096]
bio29, seg0: 0x00905000-0x00906000 [4096]
bio30, seg0: 0x00906000-0x00907000 [4096]
bio31, seg0: 0x00907000-0x00908000 [4096]
bio32, seg0: 0x00908000-0x00909000 [4096]
bio33, seg0: 0x00909000-0x0090a000 [4096]
bio34, seg0: 0x0090a000-0x0090b000 [4096]
bio35, seg0: 0x0090b000-0x0090c000 [4096]
bio36, seg0: 0x0090c000-0x0090d000 [4096]
bio37, seg0: 0x0090d000-0x0090e000 [4096]
bio38, seg0: 0x0090e000-0x0090f000 [4096]
bio39, seg0: 0x0090f000-0x00910000 [4096]
bio40, seg0: 0x00910000-0x00911000 [4096]
bio41, seg0: 0x00911000-0x00912000 [4096]
bio42, seg0: 0x00912000-0x00913000 [4096]
bio43, seg0: 0x00913000-0x00914000 [4096]
bio44, seg0: 0x00914000-0x00915000 [4096]
bio45, seg0: 0x00915000-0x00916000 [4096]
bio46, seg0: 0x00916000-0x00917000 [4096]
bio47, seg0: 0x00917000-0x00918000 [4096]
bio48, seg0: 0x00918000-0x00919000 [4096]
bio49, seg0: 0x0091a000-0x0091b000 [4096]
bio50, seg0: 0x0091b000-0x0091c000 [4096]
bio51, seg0: 0x0091c000-0x0091d000 [4096]
bio52, seg0: 0x0091d000-0x0091e000 [4096]
bio53, seg0: 0x0091f000-0x00920000 [4096]
bio54, seg0: 0x00920000-0x00921000 [4096]
bio55, seg0: 0x00921000-0x00922000 [4096]
bio56, seg0: 0x00922000-0x00923000 [4096]
bio57, seg0: 0x00923000-0x00924000 [4096]
bio58, seg0: 0x00924000-0x00925000 [4096]
bio59, seg0: 0x00925000-0x00926000 [4096]
bio60, seg0: 0x00926000-0x00927000 [4096]
bio61, seg0: 0x00927000-0x00928000 [4096]
bio62, seg0: 0x00928000-0x00929000 [4096]
bio63, seg0: 0x00929000-0x0092a000 [4096]
bio64, seg0: 0x0092a000-0x0092b000 [4096]
bio65, seg0: 0x0092b000-0x0092c000 [4096]
bio66, seg0: 0x0092c000-0x0092d000 [4096]
bio67, seg0: 0x0092d000-0x0092e000 [4096]
bio68, seg0: 0x0092e000-0x0092f000 [4096]
bio69, seg0: 0x0092f000-0x00930000 [4096]
bio70, seg0: 0x00930000-0x00931000 [4096]
bio71, seg0: 0x00931000-0x00932000 [4096]
bio72, seg0: 0x00932000-0x00933000 [4096]
bio73, seg0: 0x00933000-0x00934000 [4096]
bio74, seg0: 0x00934000-0x00935000 [4096]
bio75, seg0: 0x00935000-0x00936000 [4096]
bio76, seg0: 0x00936000-0x00937000 [4096]
bio77, seg0: 0x00937000-0x00938000 [4096]
bio78, seg0: 0x00938000-0x00939000 [4096]
bio79, seg0: 0x00939000-0x0093a000 [4096]
bio80, seg0: 0x0093a000-0x0093b000 [4096]
bio81, seg0: 0x0093b000-0x0093c000 [4096]
bio82, seg0: 0x0093c000-0x0093d000 [4096]
bio83, seg0: 0x0093d000-0x0093e000 [4096]
bio84, seg0: 0x0093e000-0x0093f000 [4096]
bio85, seg0: 0x0093f000-0x00940000 [4096]
bio86, seg0: 0x00940000-0x00941000 [4096]
bio87, seg0: 0x00941000-0x00942000 [4096]
bio88, seg0: 0x00942000-0x00943000 [4096]
bio89, seg0: 0x00943000-0x00944000 [4096]
bio90, seg0: 0x00944000-0x00945000 [4096]
bio91, seg0: 0x00945000-0x00946000 [4096]
bio92, seg0: 0x00946000-0x00947000 [4096]
bio93, seg0: 0x00947000-0x00948000 [4096]
bio94, seg0: 0x00948000-0x00949000 [4096]
bio95, seg0: 0x00949000-0x0094a000 [4096]
bio96, seg0: 0x0094a000-0x0094b000 [4096]
bio97, seg0: 0x0094b000-0x0094c000 [4096]
bio98, seg0: 0x0094c000-0x0094d000 [4096]
bio99, seg0: 0x0094d000-0x0094e000 [4096]
bio100, seg0: 0x0094e000-0x0094f000 [4096]
bio101, seg0: 0x0094f000-0x00950000 [4096]
bio102, seg0: 0x00950000-0x00951000 [4096]
bio103, seg0: 0x00951000-0x00952000 [4096]
bio104, seg0: 0x00952000-0x00953000 [4096]
bio105, seg0: 0x00953000-0x00954000 [4096]
bio106, seg0: 0x00954000-0x00955000 [4096]
bio107, seg0: 0x00955000-0x00956000 [4096]
bio108, seg0: 0x00956000-0x00957000 [4096]
bio109, seg0: 0x00957000-0x00958000 [4096]
bio110, seg0: 0x00959000-0x0095a000 [4096]
bio111, seg0: 0x0095a000-0x0095b000 [4096]
bio112, seg0: 0x0095b000-0x0095c000 [4096]
bio113, seg0: 0x0095c000-0x0095d000 [4096]
bio114, seg0: 0x0095d000-0x0095e000 [4096]
bio115, seg0: 0x0095e000-0x0095f000 [4096]
bio116, seg0: 0x0095f000-0x00960000 [4096]
bio117, seg0: 0x00960000-0x00961000 [4096]
bio118, seg0: 0x00961000-0x00962000 [4096]
bio119, seg0: 0x00962000-0x00963000 [4096]
bio120, seg0: 0x00963000-0x00964000 [4096]
bio121, seg0: 0x00964000-0x00965000 [4096]
bio122, seg0: 0x00965000-0x00966000 [4096]
bio123, seg0: 0x00966000-0x00967000 [4096]
bio124, seg0: 0x00967000-0x00968000 [4096]
bio125, seg0: 0x00968000-0x00969000 [4096]
bio126, seg0: 0x00969000-0x0096a000 [4096]
bio127, seg0: 0x0096a000-0x0096b000 [4096]
Incorrect number of segments after building list
counted 11, received 5
req nr_sec 1024, cur_nr_sec 8
nr_hw_segments = 128
segments now 5
slab error in cache_free_debugcheck(): cache `sgpool-8': double free, or memory outside object was overwritten
next prev parent reply other threads:[~2004-10-14 20:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <53CF1076699CD711B7DD0002A51363F1072A6E3A@exw-ks.ks.lsil.com>
2004-10-13 21:46 ` Question about Request Sense case in scsi_lib.c 'Dave Olien'
2004-10-13 21:56 ` James Bottomley
2004-10-13 22:09 ` 'Dave Olien'
2004-10-14 17:52 ` 'Dave Olien'
2004-10-14 18:05 ` James Bottomley
2004-10-14 20:39 ` James Bottomley [this message]
2004-10-14 0:30 ` Douglas Gilbert
2004-10-14 6:49 ` Lan Tran
2004-10-14 15:25 ` James Bottomley
2004-10-12 0:00 Dave Olien
[not found] ` <eada2a07041012092973d35415@mail.gmail.com>
2004-10-12 16:31 ` Tim Pepper
2004-10-12 16:59 ` Dave Olien
2004-10-12 17:13 ` James Bottomley
2004-10-12 17:59 ` Dave Olien
2004-10-12 20:13 ` Patrick Mansfield
2004-10-12 20:44 ` Dave Olien
2004-10-13 2:10 ` Douglas Gilbert
2004-10-13 17:56 ` Dave Olien
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1097786376.2198.43.camel@mulgrave \
--to=james.bottomley@steeleye.com \
--cc=axboe@suse.de \
--cc=dmo@osdl.org \
--cc=dougg@torque.net \
--cc=linux-scsi@vger.kernel.org \
--cc=tpepper@gmail.com \
--cc=yanling.qi@engenio.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox