Any ideas on this? Do you think it's a bug, or am I just holding it wrong? :-) On Sat, Dec 10, 2011 at 8:02 AM, Marcus Sorensen <shadowsor@xxxxxxxxx> wrote: > That keeps the 'bypassed' value from increasing, but it doesn't change > write performance. > > BEFORE: > [root@sansrv2-10 stats_day]# cat * > 27.6M > 83 > 3500 > 0 > 166 > 24380 > 40660 > 0 > > ...benchmarking... > > AFTER: > > [root@sansrv2-10 stats_day]# for i in `ls`; do echo -n "$i "; cat $i; >> done 2>/dev/null > bypassed 27.6M > cache_bypass_hits 83 > cache_bypass_misses 3500 > cache_hit_ratio 0 > cache_hits 410 > cache_miss_collisions 48879 > cache_misses 80545 > cache_readaheads 0 > > /sys/fs/bcache/60da061c-d646-4ebe-931a-d8580add411d > > average_key_size 0 > block_size 2.0k > btree_cache_size 3.2M > bucket_size 1.0M > cache_available_percent 100 > clear_stats congested 0 > congested_threshold_us 0 > dirty_data 0 > io_error_halflife 0 > io_error_limit 8 > root_usage_percent 0 > synchronous 1 > tree_depth 1 > > > On Fri, Dec 9, 2011 at 11:33 PM, Kent Overstreet > <kent.overstreet@xxxxxxxxx> wrote: >> On Fri, Dec 09, 2011 at 10:09:55AM -0700, Marcus Sorensen wrote: >>> Here's some more info. I'm running kernel 3.1.4. When I do random >>> writes, the 'bypassed' number increases in stats. Now I'm random >>> writing direct to /dev/bcache0 and get the same result. >> >> Weird. From what you're describing it sounds like throttling is screwed >> up (and it was recently), but I can't reproduce it now. >> >> Can you try echoing 0 to congested_threshold_us in the cache set dir, >> and seeing if that fixes it? >> >>> There also seems to be some work needed with clean-up, since I'm >>> unfamiliar with how bcache works I attempted to make-bcache twice, >>> thinking I'd start over. That worked, but because my cache device was >>> already registered I was unable to re-register my newly formatted >>> cache dev, got "kobject_add_internal failed for bcache with -EEXIST, >>> don't try to register things with the same name in the same >>> directory." I was still able to use my cache device via the old uuid, >>> but this will probably cause problems on reboot. Perhaps an unregister >>> file in /sys/fs/bcache would help, I also tried rmmod'ing bcache to >>> see if I could clear /sys/fs/bcache, but no luck. make-bcache should >>> perhaps check for an existing superblock, ask for confirmation, and >>> give some sort instruction on how to unregister, or do it for you if >>> you reformat. >> >> Yeah, I think for some reason bcache isn't opening the devices >> exclusively on 3.1. I'll have a look... -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
