From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: Cleanup patches Date: Sun, 16 Nov 2014 00:30:23 +0100 Message-ID: <5467E20F.8010903@gmail.com> References: <5c7c368b0711140634y569c8ce8ke4b2e813a2244ce2@mail.gmail.com> <5c7c368b0711141439u1cb89d82g8ee0928eabbae2a5@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=ZT/0r8reFOXkRy4gCG4DQ4VP513KRBv9xWbwZB92g8I=; b=RUGwDD+XReGSUWm+w4iSlhTCSyqTI7lvla15WNX8/iqmqodkV1Bn3PCtEXgC8VBa9y j6GhqlVSQR9O23HR8/KZicX2paHAhTMHueU4g/1pqAKW5iZl22wgPVWIcYD+1Jehm8HN hDT74Qj9A6CR8NFQTJxCfB5SEWMsN59vCvHmCZg6r6O1WkWfrY4o4kg+XfhIxqLNXPpM ePJYe7etRE8J/NuFtYee2HuwA8Xgx5K7AfLV+sdkCzwOYOip9w2E+VOX3r0y4z4RA/5z UScIwqKuIR6UgKFFzGlhfZqh628bGxbr40voNXq8C13ijOrfZS0wsU18wN6wMONpTjFC rZyA== In-Reply-To: Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="utf-8"; format="flowed" To: =?UTF-8?B?RHXFoWFuIMSMb2xpxIc=?= , Ivan Shapovalov , reiserfs-devel On 11/16/2014 12:06 AM, Du=C5=A1an =C4=8Coli=C4=87 wrote: > These are results from bisecting of R4 slowdown with ccreg40 plugin Hmm.. Are you sure? 2.6.10 doesn't know about ccreg... > with config and scripts I used, first double run is to see dispersion > of consecutive tests: > > Reiser4 patch Real User System > 2.6.10-2 2m46.785s 0m3.214s 1m45.286s > 2.6.10-2 2m52.700s 0m3.198s 1m43.361s > 2.6.16-5 3m32.694s 0m2.900s 1m34.698s > 2.6.19-4 3m19.672s 0m3.120s 1m33.234s > 2.6.20 3m9.582s 0m3.164s 1m28.830s > 2.6.21 7m52.960s 0m2.992s 1m28.326s > 2.6.22-2 6m57.991s 0m2.852s 1m28.258s > > > Have a nice day > > Dushan > > On Fri, Oct 24, 2014 at 11:17 PM, Du=C5=A1an =C4=8Coli=C4=87 wrote: >> OK after 7 years, can't believe how long ago it was, I decided to di= g up >> some ancient hw and to try again to do this bisect. >> Questions: >> 1. Would it still be useful? >> 2. Any other tests that I can do on those old kernels that can be of= value? >> 3. What would be best bisect range? Oldest and newest kernel? >> >> On Nov 14, 2007 11:39 PM, "Edward Shishkin" >> wrote: >>> On 11/15/07, Dushan Tcholich wrote: >>>> ... >>>>>> Well. There is a problem: starting from some point, performance = of >>>>>> reiser4 is substantially dropped for unknown reasons. As I remem= ber, >>>>>> there were a lot of complaints about it. Also I have made a brie= f >>>>>> test not so long ago (copy of linux source tree located in ramfs= to >>>>>> reiser4 partition): yeah, it is 3 times worse then it ought to b= e, >>>>>> "vmstat 2" reports low bo-activity (something like 10000 blocks/= s, >>>>>> instead of usual ~30000). >>>>>> >>>>>> It would be nice to find a changeset which kills performance. >>>>>> >>>>>> Would you please look at this? It is non-trivial task, so every >>>>>> result would be ok (say, to know the first kernel in -mm series >>>>>> with slow reiser4). >>>>>> >>>>>> Hints: >>>>>> >>>>>> 1. The problem is in (default) unix-file plugin (nobody maintain= ed >>>>>> this for a long of time), so compression should be disabled. >>>>>> 2. I guess it should be something like bisecting. >>>>>> 3. I think that the problem appeared in ~2.6.17-mmXX kernel when >>>>>> vs sent vfs patches with batch_write methods, and then Andr= ew >>>>>> Morton evicted them because of some problems. However, >>>>>> I might be wrong here! >>>>>> >>>>> If you could give me an easy way to benchmark (guide me by hand),= I >>>>> could try to bisect it. >>>>> It would be easier if -mm could be bisected using git. >>>>> But my / is on r4+cc, so I don't know how could I do it? Maybe on >>>>> other machine? >>> Yes! Compression announced 15 March 2007, and it may happen >>> that some kernel you will need to boot are not support your "/". >>> So for bisecting you need the following: >>> 1. a machine with >=3D 512M RAM and "/" formatted with some fs >>> supported by old kernels. >>> 2. a spare partition. >>> 3. enable ramfs (it seems it is enabled by default in most distros)= =2E >>> 4. put a tarball-to-copy in some working directory (I had >>> linux-2.6.9.tar.gz) >>> >>> Note, that some old -mm kernels are not compilable/bootable >>> (if so, pull the "hotfixes" patches from akpm's directory on kernel= =2Eorg) >>> >>> 5. edit the attached patches in accordance with your configurations >>> 6. build and boot the testing kernel with reiser4 debug disabled >>> (I think no needs to boot in single mode, or discard kde, etc.= =2E) >>> 7. run "vmstat 2" >>> 8. run ./prepare_copy.sh && ./ncopy on another console >>> >>> I have the following: >>> real 6m27.970s >>> user 0m2.116s >>> sys 1m4.972s >>> >>> God, it is fairly bad results: On my machine real time should be >>> something like 2m20...... -- To unsubscribe from this list: send the line "unsubscribe reiserfs-deve= l" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html