On Sat, Jan 13, 2007 at 08:22:18AM +0100, Willy Tarreau wrote: > > > > Which makes me think that we aren't writing back fast enough. If I > > mount the drive "sync" the issue clearly goes away. > > > > It appears from an strace we are doing ftruncate64(5, 178257920) when > > we OOM. > > > > Any ideas on VM parameters to tweak so we throttle this from occurring? > > Take a look at /proc/sys/vm/bdflush. There are several useful parameters > there (doc is in linux-xxx/Documentation). For instance, the first column > is the percentage of memory used by writes before starting to write on > disk. When using tcpdump intensively, I lower this one to about 1%. > > Willy
Hi Willy, I know you're doing a great job on keeping the 2.4 kernel in shape, but do you also have a good advice for people with more recent kernels? (hint: the file /proc/sys/vm/bdflush is missing) Regards, Toon. $ uname -a Linux shuttle 2.6.18-gentoo-r6 #1 Sat Jan 13 12:00:15 CET 2007 x86_64 AMD Athlon(tm) 64 Processor 3200+ AuthenticAMD GNU/Linux $ ls -l /proc/sys/vm/ totaal 0 -rw-r--r-- 1 root root 0 jan 13 14:09 block_dump -rw-r--r-- 1 root root 0 jan 13 14:09 dirty_background_ratio -rw-r--r-- 1 root root 0 jan 13 14:09 dirty_expire_centisecs -rw-r--r-- 1 root root 0 jan 13 14:09 dirty_ratio -rw-r--r-- 1 root root 0 jan 13 14:09 dirty_writeback_centisecs -rw-r--r-- 1 root root 0 jan 13 14:09 drop_caches -rw-r--r-- 1 root root 0 jan 13 14:09 hugetlb_shm_group -rw-r--r-- 1 root root 0 jan 13 14:09 laptop_mode -rw-r--r-- 1 root root 0 jan 13 14:09 legacy_va_layout -rw-r--r-- 1 root root 0 jan 13 14:09 lowmem_reserve_ratio -rw-r--r-- 1 root root 0 jan 13 14:09 max_map_count -rw-r--r-- 1 root root 0 jan 13 14:09 min_free_kbytes -rw-r--r-- 1 root root 0 jan 13 14:09 nr_hugepages -r--r--r-- 1 root root 0 jan 13 14:09 nr_pdflush_threads -rw-r--r-- 1 root root 0 jan 13 14:09 overcommit_memory -rw-r--r-- 1 root root 0 jan 13 14:09 overcommit_ratio -rw-r--r-- 1 root root 0 jan 13 14:09 page-cluster -rw-r--r-- 1 root root 0 jan 13 14:09 panic_on_oom -rw-r--r-- 1 root root 0 jan 13 14:09 percpu_pagelist_fraction -rw-r--r-- 1 root root 0 jan 13 14:09 swappiness -rw-r--r-- 1 root root 0 jan 13 14:09 swap_token_timeout -rw-r--r-- 1 root root 0 jan 13 14:09 vfs_cache_pressure - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
