This issue has been tracked down more. This bug does NOT appear if I disable preemtive kernel. Maybe this helps.
Nick Piggin wrote:
Christian Schmid wrote:
I already tried with 300 KB and even used a perl-hash as a horrible-slow buffer for a readahead-replacement. It still slowed down on the syswrite to the socket. Thats the strange thing.
Do you have to use manual readahead though? What is the performance like if you just let the kernel do its own thing? The kernel's readahead provides things like automatic scaling and thrashing control, so if possible you should just stick to that.
Although you may want to experiment with the maximum readahead on your working disks: /sys/block/???/queue/read_ahead_kb
Also, can we get a testcase (ie. minimal compilable code) to reproduce this problem?
Thanks, Nick
- 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/