On 10 February 2014 23:46, Kent Overstreet <kmo@xxxxxxxxxxxxx> wrote: > On Mon, Feb 10, 2014 at 02:15:14PM +0100, Josep Lladonosa wrote: >> On 10 February 2014 12:40, Gabriel de Perthuis <g2p.code@xxxxxxxxx> wrote: >> >> Hello, >> >> >> >> I am using bcache in my laptop (RAM 32 GiB). I have been using it >> >> perfectly for a month. ext4 + bcache. >> >> >> >> Yesterday, system did not want do to a normal startup. Messages where >> >> from udev out of memory (and udevadm killed?) and system was not >> >> mounting / (/dev/bcache0). >> >> >> >> [ 6.823222] bcache-register invoked oom-killer: gfp_mask=0x82d2, >> >> order=0, oom_score_adj=0 >> > >> > Build your kernel with CONFIG_COMPACTION. I've added it to the FAQ: >> > http://bcache.evilpiepirate.org/~kent/bcache/FAQ/ >> >> >> Hello Gabriel, >> >> Thanks for your reply. >> >> My .config file has already: >> ... >> CONFIG_COMPACTION=y > > I looked at the allocations done in bcache_device_init(), those aren't high > order page allocations (they're vmalloc allocations) so compaction won't help > here. > >> ... >> >> I have been digging around to find information and sometimes bugs come >> related to unsigned variables and their operations when storing large >> numbers (reserved memory?). Kernel is 64 bits. Memory is 32 GiB. >> Perhaps it could happen that the allocated memory is not totally >> freed. >> >> When kernel has been able to boot with 32 GiB (having bcache0 messed >> up and bcache1 mountable), it seems that bcache has more than 16 GiB >> allocated and kept. > > Woah, really? If so that's bad - I don't see how that follows (or am I > misreading) from your numbers, can you show a before and after when you bring > bcache up? What I have done is: - boot computer in Debian (kernel&bcache-tools ready) from an USB with the caching device unplugged and backing plugged. Booting O.K. with 32 GiB of RAM. - plug caching device to external SATA. Bcache detects it, but... - bcache0 and bcache1 are shown (I could do a fast "ls" for /sys/block). - After some seconds, system freezes. I could detach cahing device and remake it and see if the same happens again, but anyway the cause of this behaviour will still be there. Josep > >> >> -Free memory with kernel 3.11.0-rc7 with 32GiB and bcache0 (halved?) >> and bcache1 (mounted) >> >> $ head -2 /proc/meminfo >> MemTotal: 32913872 kB >> MemFree: 12376640 kB >> >> >> - Free memory with kernel 3.12.9 with mem=16G and bcache0 (mounted) >> >> $ head -2 /proc/meminfo >> MemTotal: 15602144 kB >> MemFree: 14005372 kB >> >> >> >> > >> > >> > -- >> > 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 >> >> >> >> -- >> -- >> Salutacions...Josep >> -- >> -- >> 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 -- -- Salutacions...Josep -- -- 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
