On 11/06/2017 09:21 AM, Paolo Valente wrote: > >> Il giorno 06 nov 2017, alle ore 17:13, Jens Axboe <axboe@xxxxxxxxx> ha scritto: >> >> On 11/06/2017 09:11 AM, Paolo Valente wrote: >>> >>>> Il giorno 06 nov 2017, alle ore 16:47, Paolo Valente <paolo.valente@xxxxxxxxxx> ha scritto: >>>> >>>>> >>>>> Il giorno 06 nov 2017, alle ore 16:00, Tejun Heo <tj@xxxxxxxxxx> ha scritto: >>>>> >>>>> Hello, >>>>> >>>>> On Sun, Nov 05, 2017 at 07:21:01PM -0700, Jens Axboe wrote: >>>>>> It's pointless to give up on this so soon, when no effort has apparently >>>>>> been dedicated to figuring out what the actual issue is yet. So no, no >>>>>> patch that will just disable the stats is going to be accepted. >>>>>> >>>>>> That said, I have no idea who uses these stats. Surely someone can >>>>>> answer that question. Tejun? >>>>> >>>>> Except for the basic bytes / ios counts, it's all debug fluff, which >>>>> should have been hidden behind a debug boot param or go under debugfs. >>>>> I'm not sure we can get rid of them at this point for cfq but I don't >>>>> see why we'd have them for bfq. >>>>> >>>> >>>> Ok, then I think this is the right time to ask you what I can throw >>>> way for bfq. According to your documentation, basic non-debug stats >>>> should be: >>>> >>>> blkio.time >>>> blkio.time_recursive >>>> blkio.sectors >>>> blkio.io_service_bytes >>>> blkio.io_service_bytes_recursive >>>> blkio.io_serviced >>>> blkio.io_serviced_recursive >>>> blkio.io_service_time >>>> blkio.io_service_time_recursive >>>> blkio.io_wait_time >>>> blkio.io_wait_time_recursive >>>> blkio.io_merged >>>> blkio.io_merged_recursive >>>> blkio.io_queued >>>> blkio.io_queued_recursive >>>> >>>> So, I have to keep them in bfq, right? Or is there something I can >>>> remove for bfq, in your opinion? Of course, I would be very happy to remove stuff! >>>> >>> >>> Or, more mildly, could some of these stats be moved behind >>> CONFIG_DEBUG_BLK_CGROUP? >> >> It'd be nice to have them be runtime enabled, but I don't think >> that's a hard requirement at all. > > So, you mean *all* stats dynamically enabled/disabled, and disabled by > default. Plus, some of them also statically filtered, that is > enabled/disabled, through CONFIG_DEBUG_BLK_CGROUP. Is my > understanding correct? If it is, we will be happy to do it. If you go the enable/disable route, don't make them depend on DEBUG_BLK_CGROUP at all. Just have them be default off, with some way to switch them on. -- Jens Axboe
