Messages in this thread | | | Date | Fri, 17 Apr 2015 08:26:11 -0600 | From | Jens Axboe <> | Subject | Re: Upstream kernel fails to run on qemu-sparc64 due to commit 889fa31f0 (blk-mq: reduce unnecessary software queue looping) |
| |
On 04/17/2015 07:32 AM, Guenter Roeck wrote: > On Thu, Apr 16, 2015 at 11:32:20PM -0700, Guenter Roeck wrote: >> Hi, >> >> my qemu-sparc64 tests fail to run with kernel v4.0-7245-ga39ef1a7c609. >> Bisect points to commit 889fa31f00b ("blk-mq: reduce unnecessary software >> queue looping"). Reverting this commit fixes the problem. >> >> I had a look into the commit, but I have no idea what might be wrong. >> >> I made the bisect log, images, configuration file, root file system, and directions >> on how to run the images available at https://urldefense.proofpoint.com/v1/url?u=http://server.roeck-us.net/qemu/sparc64&k=ZVNjlDMF0FElm4dQtryO4A%3D%3D%0A&r=3JMVyziIyZtZ5cv9eWNLwQ%3D%3D%0A&m=%2FUVX9MC8j8RmqOwlL6HnyBe%2FFSO5xSJdG3GTTzADFYk%3D%0A&s=caaf39bb4246d5223f9dea93771fdb075f9046b6fdf1822b7da21d7665da71d5. >> >> Please let me know if there is any other information I can provide. >> > As additional information: > > + * Set the map size to the number of mapped software queues. > + * This is more accurate and more efficient than looping > + * over all possibly mapped software queues. > + */ > + map->map_size = hctx->nr_ctx / map->bits_per_word; > > On my system, hctx->nr_ctx is 1, and map->bits_per_word is 8. > Thus map->map_size is set to 0, which doesn't make much sense.
> The system comes up if I replace the above code with > map->map_size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word); > > I have no idea if that is the correct fix, though.
Ugh, yes indeed, looks like the <= was lost from a previous patch. Now I wonder why it I didn't see any hangs with this... Thanks for reporting, I'll get a fix in today.
-- Jens Axboe
| |