2.6.5-rc2-mm2 and direct_read_under

From: Daniel McNeil
Date: Fri Mar 19 2004 - 11:52:01 EST


I re-ran direct_read_under test (6 copies) on 2.6.4-rc2-mm2:

ext3 failed within 2 hours.

ext2 ran overnight without errors.

Daniel

On Thu, 2004-03-18 at 11:10, Daniel McNeil wrote:
> On Thu, 2004-03-18 at 10:47, Chris Mason wrote:
> > On Thu, 2004-03-18 at 12:53, Daniel McNeil wrote:
> > > I'm ran 2.6.4-mm2 plus the 2 wait_on_page_range() patches,
> > > the test_set_page_writeback() patch and clear_page_dirty_for_io patch
> > > overnight.
> > >
> > > 6 copies of direct_read_under test on 8-cpu system on 1
> > > ext3 file system in 1 directory on a scsi disk.
> > > (http://developer.osdl.org/daniel/AIO/TESTS/direct_read_under.c)
> > >
> > > 5 of the 6 tests saw uninitialized data within 2 hours.
> > > The sixth test ran overnight.
> >
> > Do you still have the errors generated? I wondering how big the range
> > of uninitialized data was. When I was bug hunting yesterday, I saw
> > ranges from 64k to 32mb in size, which was why I decided writes weren't
> > getting to the disk at all.
> >
> > It might be interesting to try with data=writeback, or on ext2. Things
> > might be easier to track if we're not worried about ll_rw_block.
> >
> > It might also be interesting to significantly lower the size of the
> > reads and writes done by direct_read_under, or anything else you can
> > think of to get the reproduce time down to something smaller than 2
> > hours...
> >
> > It's probably a good idea to upgrade to 2.6.5-rc1-mm2, just so we're all
> > staring at the same code.
> >
> > -chris
> >
>
> Chris,
>
> Still have the data:
> 63 pages (258048 bytes)
> 90 pages (368640 bytes)
> 139 pages (569344 bytes)
> 30 pages (122880 bytes)
> 87 pages (356352 bytes)
>
>
> I'm rebooting to 2.6.5-rc1-mm2 and will re-run. I have do have
> versions of direct_read_under that do smaller i/o and also
> 1 that does forks off and does 'sync' calls every few seconds.
>
> I'll give ext2 and try as well.
>
> Daniel
>
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