> Going through various forum messages and bug reports (for Debian: > https://lists.debian.org/debian-kernel/2015/03/msg00060.html for Arch: > https://bugs.archlinux.org/task/38843 for some other distro: > https://groups.google.com/forum/#!msg/esos-users/NXp8tG7sVE8/QXZyPdZ2saIJ > ) it looks like the bcache_writeback kernel thread, being in > uninterruptible sleep, keeps the load average at 1.0 (or maybe more) > always. Could you please confirm this ? Try the attached patches that I've been collecting over the past year or two. I do not believe they have been merged into mainline (BUT SOMEONE NEEDS TO). I am not sure that these address the load bug, but if the load is being increased by a large amount of dmesg output caused by rcu traces, then the patches will help. -Eric > > - this behaviour should be described in the bcache documentation > because it feels to me (and many other) like a true gotcha. It's > apparently completely undocumented. A "CAVEATS" section at the > bottom of bcache.txt in the kernel Documentation explaining this > would be nice, what do you think? > > - Is there any way around this? Some people seem to grow uneasy (maybe > irrationnally) having a constant load on an otherwise unused system > (I know that a sleeping thread actually does nothing, but many > system administrators can't wrap their head around this idea). > > I've tried some advice I've found on the web, like switching to > writethrough and "echo 0 > /sys/block/bcache0/bcache/writeback_running" > but to absolutely no effect. > > Any advice and idea is welcome :) > > -- > ------------------------------------------------------------------------ > Emmanuel Florac | Direction technique > | Intellique > | > | +33 1 78 94 84 02 > ------------------------------------------------------------------------ > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >