> I'm sorry to piggy-back this thread. > > Could it be what I'm experiencing in the following bugzilla report: > http://bugzilla.kernel.org/show_bug.cgi?id=7372 > > As I explained in the report, I see this issue only since 2.6.18. > So if your concern is related to mine, what could have changed between > 2.6.17 and 2.6.18 related to this?
I don't think it's 2.6.x related, it's been under the sheets from start. Related to your problem in the 7372 bug: Pages are kept in memory for re-use, which is fast and fine except for: 1) data without re-use value or even single use 2) applications _do not_ advise the kernel how to cache pages related to there self generated i/o. POSIX does provide mechanisms to properly do so. But the kernel should help these poor apps. To minimize your MySQL backup cp(1) problem, try this workaround: cat ./cp_direct.sh #!/bin/sh dd if=$1 of=$2 bs=1M iflag=direct oflag=direct Combine this with [/etc/sysctl.conf]: vm.vfs_cache_pressure = 1 vm.dirty_ratio = 2 vm.dirty_background_ratio = 1 This should reduce both the stress on the vm and response latency during interactive work. -- Leroy - 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/