Hi lists, I'd like to report the following problem : after ~ 10 days' uptime on a Debian 2.6.26-1-686 kernel, my system becomes extremely sluggish and unresponsive and the OOM-killer starts targeting even innocent processes like identd or rsync (when the swap is disabled). The machine is low on RAM (192 MB) but this has never been a problem before. As for the slowness, strace shows that the brk() syscall takes ages to complete; the blocking processes are in the D state (and for some reason the kernel gives no wchan info). Free reports a large and constantly growing 'buffers' figure (more than 50% of the available memory). No userland processes seems to be consuming lare amounts of memory (sum of RSS in 'ps aux' is about 30 megs), and the overall system is mostly idle. for instance, the following command reports $ free ; dpkg -l '*' >/dev/null; dmesg | tail -n 2 total used free shared buffers cached Mem: 190356 178920 11436 0 126104 12520 -/+ buffers/cache: 40296 150060 Swap: 0 0 0 /* Waits a minute or so */ Killed [811245.911859] Out of memory: kill process 6639 (dpkg-query) score 7292 or a child [811245.911972] Killed process 6639 (dpkg-query) Config has nothing unusual except that all fs are ext4, which I am begining to suspect may be the culprit, as every night some process stat()s and read()s something like 850,000 files, which is maybe fs-stressing; also, umounting then remounting /home makes the 'buffers' drop from 127304 to 55920 and partially solves the problem. For info, on umount the last lines in the dmesg read: [811842.209432] EXT4-fs: mballoc: 12288 blocks 12288 reqs (0 success) [811842.209547] EXT4-fs: mballoc: 13038 extents scanned, 5902 goal hits, 6315 2^N hits, 0 breaks, 0 lost [811842.209638] EXT4-fs: mballoc: 768 generated and it took 12577042 [811842.209695] EXT4-fs: mballoc: 1588424 preallocated, 371043 discarded [811842.372165] kjournald2 starting. Commit interval 5 seconds [811842.373381] EXT4 FS on hda4, internal journal [811842.373473] EXT4-fs: mounted filesystem with ordered data mode. [811842.373529] EXT4-fs: file extents enabled [811842.374013] EXT4-fs: mballoc enabled I believe the problem appeared in 2.6.25, but I am not sure. Regards, Quentin Godfroy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html