Hi I would like to report a memory management bug where the dirty pages count underflowed. It happened after some time that the Dirty pages count underflowed, as can be seen in /proc/meminfo. The underflow condition was persistent, /proc/meminfo was showing the big value even when the system was completely idle. The counter never returned to zero. The system didn't crash, but it became very slow - because of the big value in the "Dirty" field, lazy writing was not working anymore, any process that created a dirty page triggered immediate writeback, which slowed down the system very much. The only fix was to reboot the machine. The kernel version where this happened is 3.14.23. The kernel is compiled without SMP and with peemption. The system is single-core 32-bit x86. The bug probably happened during git pull or apt-get update, though one can't be sure that these commands caused it. I see that 3.14.24 containes some fix for underflow (commit 6619741f17f541113a02c30f22a9ca22e32c9546, upstream commit abe5f972912d086c080be4bde67750630b6fb38b), but it doesn't seem that that commit fixes this condition. If you have a commit that could fix this, say it. Mikulas MemTotal: 253504 kB MemFree: 6128 kB MemAvailable: 54956 kB Buffers: 1376 kB Cached: 45284 kB SwapCached: 40432 kB Active: 105596 kB Inactive: 111672 kB Active(anon): 82772 kB Inactive(anon): 88604 kB Active(file): 22824 kB Inactive(file): 23068 kB Unevictable: 4 kB Mlocked: 4 kB SwapTotal: 4242896 kB SwapFree: 4144248 kB Dirty: 4294944344 kB Writeback: 8 kB AnonPages: 167484 kB Mapped: 7808 kB Shmem: 768 kB Slab: 19072 kB SReclaimable: 10448 kB SUnreclaim: 8624 kB KernelStack: 1136 kB PageTables: 2032 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 4369648 kB Committed_AS: 398032 kB VmallocTotal: 778184 kB VmallocUsed: 38316 kB VmallocChunk: 707540 kB AnonHugePages: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 4096 kB DirectMap4k: 20416 kB DirectMap4M: 241664 kB -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>