From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28 Date: Thu, 18 Sep 2008 09:12:50 +0200 Message-ID: <1221721970.5003.9.camel@marge.simson.net> References: <1221306287.5213.111.camel@marge.simson.net> <48CD1D25.9080301@linux-foundation.org> <1221421907.4597.24.camel@marge.simson.net> <1221475440.4784.39.camel@marge.simson.net> <1221568105.5020.17.camel@marge.simson.net> <1221626391.5043.13.camel@marge.simson.net> <1221627676.5125.3.camel@marge.simson.net> <20080917104044.GC18764@elte.hu> <1221651701.5102.17.camel@marge.simson.net> <20080917124943.GA7738@elte.hu> <1221657111.5511.14.camel@marge.simson.net> <1221659858.8818.13.camel@marge.simson.net> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1221659858.8818.13.camel-YqMYhexLQo1vAv1Ojkdn7Q@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Ilpo =?ISO-8859-1?Q?J=E4rvinen?= Cc: Ingo Molnar , Christoph Lameter , "Rafael J. Wysocki" , LKML , kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Wed, 2008-09-17 at 15:57 +0200, Mike Galbraith wrote: > On Wed, 2008-09-17 at 16:36 +0300, Ilpo J=C3=A4rvinen wrote: > > On Wed, 17 Sep 2008, Mike Galbraith wrote: > >=20 > > > On Wed, 2008-09-17 at 14:49 +0200, Ingo Molnar wrote: > > >=20 > > > > git log --pretty=3Dformat:"%h: %s" 2069f45..847106f | grep -viE= \ > > > > 'block|alsa|pcmcia|sound|Merge|iosched|blk|DAC960|scsi|s390|par= ide|pktcdvd|filter|cdrom|drm' > > > >=20 > > > > gives us: > > > >=20 > > > > 7daf705: Start using the new '%pS' infrastructure to print sym= bols > > > > 6f0f0fd: security: remove register_security hook > > > > 93cbace: security: remove dummy module fix > > > > 5915eb5: security: remove dummy module > > > > b478a9f: security: remove unused sb_get_mnt_opts hook > > > > 32502b8: splice: fix generic_file_splice_read() race with page= invalidation > > > > 8b3d356: ramfs: enable splice write > > > > a144ff0: xen: Avoid allocations causing swap activity on the r= esume path > > > >=20 > > > > which really only leaves that security commit your bisection fi= ngered.=20 > > > > Which _slightly_ raises its likelyhood of being implicated. Str= ucture=20 > > > > size changes can move two formerly far-apart netperf-relevant s= ymbols on=20 > > > > the same cacheline, which can start cache ping-pong-ing badly. > > >=20 > > > I sure hope it's something like ping-pong, it's driving me NUTS. > >=20 > > How about dividing the problem to smaller blocks then by restoring=20 > > parts of the change... >=20 > Well, what I've done is check out the "bad" tree, reverted every darn > commit between there and the "good" tree, and then reverted the rever= ts > so I have a nice merge-free line and don't have to remember to think > backward. (probably sounds silly to git-foo masters) I'll try > bisecting that in the a.m. and see what happens. It bisected to 1c9ce52. Reverting that in 27.git had the expected result, nada. Full bisection/test log below - you can jump straight to post run sanity checks. I'm torn between building a straight line tree from v2.6.26 through git.today and bisecting that sucker, or exorcising netperf from my box and swearing a sacred oath to never download the damned thing again. Nuking netperf is most attractive option. 1e65e841bb5584136ed6047c55cf77532afbbb55 is first bad commit commit 1e65e841bb5584136ed6047c55cf77532afbbb55 Author: Mike Galbraith Date: Wed Sep 17 14:55:50 2008 +0200 Revert "Revert "block: export "ro" attribute"" This reverts commit 2c8803af5c1bf41200167f29349f7f1396683a51. :040000 040000 08ca8ba7ff3f9506a5462b4122256356cae28ceb bef679485bc924a= d1dc867858ebda1b68196b5a8 M block git bisect start # good: [7804ad865f7d0cd9bdc51da601772ce4d2e252ca] Revert "[ALSA] soc -= tlv320aic3x - revisit clock setup" git bisect good 7804ad865f7d0cd9bdc51da601772ce4d2e252ca # bad: [2846693a63a34ac6d582dd55a7e00605b49b1cec] Revert "Revert "[S390= ] sclp_tty: Fix scheduling while atomic bug."" git bisect bad 2846693a63a34ac6d582dd55a7e00605b49b1cec # bad: [70477f86f63640be2dd1d8968aeb47870a5c21c6] Revert "Revert "xen/b= lkfront: Make sure we don't use bounce buffers, we don't need them."" git bisect bad 70477f86f63640be2dd1d8968aeb47870a5c21c6 # good: [7c6ccb520424939deff0a50f3fae621c6477dbbe] Revert "Revert "ALSA= : hda - Add bdl_pos_adj option"" git bisect good 7c6ccb520424939deff0a50f3fae621c6477dbbe # good: [66036beae94f043f99044e285935486126a9c4bd] Revert "Revert "pcmc= ia: fix Alchemy warnings"" git bisect good 66036beae94f043f99044e285935486126a9c4bd # good: [6b7b5ef18871c8f7c15eedc6eb53270eaf8bc613] Revert "Revert "ALSA= : hda - Added SSID for 'Fujitsu Siemens Amilo M1451G' laptop"" git bisect good 6b7b5ef18871c8f7c15eedc6eb53270eaf8bc613 # good: [024905ea4b2d1ab5d6b845ba84ddfc0857fb2d2a] Revert "Revert "ALSA= : hda - Add MacBook 3.1 support"" git bisect good 024905ea4b2d1ab5d6b845ba84ddfc0857fb2d2a # good: [4bbe3501e06eddaa4900894efa519f1167cb8624] Revert "Revert "as-i= osched: properly protect ioc_gone and ioc count"" git bisect good 4bbe3501e06eddaa4900894efa519f1167cb8624 # good: [e124683c1cd5c73c494f9ea6cee8a71e68bb70ca] Revert "Revert "Adde= d in user-injected messages into blk traces"" git bisect good e124683c1cd5c73c494f9ea6cee8a71e68bb70ca # bad: [f148fae0bc009aa23122c5762368a1a16bb55b86] Revert "Revert "block= : kill request_queue_t"" git bisect bad f148fae0bc009aa23122c5762368a1a16bb55b86 # bad: [1e65e841bb5584136ed6047c55cf77532afbbb55] Revert "Revert "block= : export "ro" attribute"" git bisect bad 1e65e841bb5584136ed6047c55cf77532afbbb55 v2.6.26-974-g2846693 (847106f) 16384 87380 1 1 60.00 94350.45 16384 87380 1 1 60.01 95857.25 16384 87380 1 1 60.00 95334.84 16384 87380 1 1 60.00 95052.11 v2.6.26-659-g7804ad8 (2069f45) 16384 87380 1 1 60.00 98630.64 16384 87380 1 1 60.00 98653.14 16384 87380 1 1 60.00 99162.65 16384 87380 1 1 60.00 98652.38 v2.6.26-816-g70477f8 (call it bad) 16384 87380 1 1 60.00 95532.19 16384 87380 1 1 60.01 96211.39 16384 87380 1 1 60.01 96246.73 16384 87380 1 1 60.01 96286.40 v2.6.26-737-g7c6ccb5 16384 87380 1 1 60.00 98478.00 16384 87380 1 1 60.00 99221.33 16384 87380 1 1 60.00 98930.70 16384 87380 1 1 60.00 98958.73 v2.6.26-776-g66036be 16384 87380 1 1 60.00 97958.10 16384 87380 1 1 60.01 98683.80 16384 87380 1 1 60.01 98515.34 16384 87380 1 1 60.00 98396.11 v2.6.26-796-g6b7b5ef 16384 87380 1 1 60.00 99047.21 16384 87380 1 1 60.00 98095.23 16384 87380 1 1 60.00 99811.18 16384 87380 1 1 60.00 98651.32 v2.6.26-806-g024905e 16384 87380 1 1 60.00 98823.46 16384 87380 1 1 60.00 98959.11 16384 87380 1 1 60.00 98709.95 16384 87380 1 1 60.00 99042.13 v2.6.26-811-g4bbe350 16384 87380 1 1 60.00 98144.99 16384 87380 1 1 60.01 99023.30 16384 87380 1 1 60.01 98685.45 16384 87380 1 1 60.01 98606.18 v2.6.26-813-ge124683 16384 87380 1 1 60.00 98458.18 16384 87380 1 1 60.00 98163.92 16384 87380 1 1 60.00 98115.62 16384 87380 1 1 60.00 98633.62 v2.6.26-815-gf148fae 16384 87380 1 1 60.00 95649.91 16384 87380 1 1 60.00 96292.34 16384 87380 1 1 60.00 96043.82 16384 87380 1 1 60.00 96093.81 v2.6.26-814-g1e65e84 16384 87380 1 1 60.00 94906.81 16384 87380 1 1 60.00 95445.05 16384 87380 1 1 60.01 94698.68 16384 87380 1 1 60.00 94938.65 Post bisection checkouts ------------------------------------------------ v2.6.26-rc8-208-g02c6230 16384 87380 1 1 60.00 98392.94 16384 87380 1 1 60.00 98199.96 16384 87380 1 1 60.00 98534.27 16384 87380 1 1 60.00 98501.02 v2.6.26-rc8-209-g1c9ce52 16384 87380 1 1 60.00 97583.88 16384 87380 1 1 60.00 97326.23 16384 87380 1 1 60.00 97582.80 16384 87380 1 1 60.00 97568.63 v2.6.26-814-g1e65e84 16384 87380 1 1 60.00 94856.33 16384 87380 1 1 60.00 94594.03 16384 87380 1 1 60.00 94751.74 16384 87380 1 1 60.01 96825.28 v2.6.26-813-ge124683 16384 87380 1 1 60.00 97550.64 16384 87380 1 1 60.00 98024.28 16384 87380 1 1 60.00 98486.85 16384 87380 1 1 60.00 98493.41 marge:..git/linux-2.6 # git rev-list v2.6.26-813-ge124683..v2.6.26-814-= g1e65e84 1e65e841bb5584136ed6047c55cf77532afbbb55 marge:..git/linux-2.6 # git show 1e65e841bb5584136ed6047c55cf77532afbbb= 55 commit 1e65e841bb5584136ed6047c55cf77532afbbb55 Author: Mike Galbraith Date: Wed Sep 17 14:55:50 2008 +0200 Revert "Revert "block: export "ro" attribute"" =20 This reverts commit 2c8803af5c1bf41200167f29349f7f1396683a51. diff --git a/block/genhd.c b/block/genhd.c index b922d48..43e468e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -400,6 +400,14 @@ static ssize_t disk_removable_show(struct device *= dev, (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); } =20 +static ssize_t disk_ro_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk =3D dev_to_disk(dev); + + return sprintf(buf, "%d\n", disk->policy ? 1 : 0); +} + static ssize_t disk_size_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -472,6 +480,7 @@ static ssize_t disk_fail_store(struct device *dev, =20 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); +static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL); static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL); @@ -483,6 +492,7 @@ static struct device_attribute dev_attr_fail =3D static struct attribute *disk_attrs[] =3D { &dev_attr_range.attr, &dev_attr_removable.attr, + &dev_attr_ro.attr, &dev_attr_size.attr, &dev_attr_capability.attr, &dev_attr_stat.attr,