Messages in this thread | | | Date | Wed, 13 Sep 2006 10:23:21 -0400 | From | "John Stoffel" <> | Subject | Re: What's in linux-2.6-block.git |
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>>>>> "Al" == Al Boldi <a1426z@gawab.com> writes:
Al> Jens Axboe wrote: >> On Wed, Sep 13 2006, Al Boldi wrote: >> > Jens Axboe wrote: >> > > This lists the main features of the 'block' branch, which is bound for >> > > Linus when 2.6.19 opens: >> > > >> > > - Splitting of request->flags into two parts: >> > > - cmd type >> > > - modified flags >> > > Right now it's a bit of a mess, splitting this up invites a cleaner >> > > usage and also enables us to implement generic "messages" passed on >> > > the regular queue for the device. >> > > >> > > - Abstract out the request back merging and put it into the core io >> > > scheduler layer. Cleans up all the io schedulers, and noop gets >> > > merging for "free". >> > > >> > > - Abstract out the rbtree sorting. Gets rid of duplicated code in >> > > as/cfq/deadline. >> > > >> > > - General shrinkage of the request structure. >> > > >> > > - Killing dynamic rq private structures in deadline/as/cfq. This >> > > should speed up the io path somewhat, as we avoid allocating several >> > > structures (struct request + scheduler private request) for each io >> > > request. >> > > >> > > - meta data io logging for blktrace. >> > > >> > > - CFQ improvements. >> > > >> > > - Make the block layer configurable through Kconfig (David Howells). >> > > >> > > - Lots of cleanups. >> > >> > Does it also address the strange "max_sectors_kb<>192 causes a >> > 50%-slowdown" problem? >> >> (remember to cc me/others when replying, I can easily miss lkml >> messages for several days otherwise). >> >> It does not, the investigation of that is still pending I'm afraid. The >> data is really puzzling, I'm inclined to think it's drive related. Are >> you reproducing it just one box/drive, or on several?
Al> Several boxes, same drive.
Al> /dev/hda:
Al> ATA device, with non-removable media Al> Model Number: WDC WD1200JB-00DUA0 Al> Serial Number: WD-WMACM1007651 Al> Firmware Revision: 65.13G65 Al> Standards: Al> Supported: 6 5 4 3 Al> Likely used: 6
I've got a pair of drives which are very close in model type, and I can run some non-destructive tests on them if you like to confirm what's going on here if you like:
/dev/hde:
ATA device, with non-removable media Model Number: WDC WD1200JB-00CRA1 Serial Number: WD-WMA8C4365875 Firmware Revision: 17.07W17 Standards: Supported: 5 4 3 Likely used: 6 jfsnew:~> sudo hdparm -I /dev/hdg | head
/dev/hdg:
ATA device, with non-removable media Model Number: WDC WD1200JB-00EVA0 Serial Number: WD-WMAEK2844058 Firmware Revision: 15.05R15 Standards: Supported: 6 5 4 Likely used: 6
The drives have different defaul max_sectors too:
> cat /sys/block/hdg/queue/max_sectors_kb 512 > cat /sys/block/hde/queue/max_sectors_kb 128
Let me know your test method and I'll run it here and post the results.
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