On Wed, 17 Nov 2010 12:27:20 +0800 Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > On a simple test of 100 dd, it reduces the CPU %system time from 30% to 3%, and > improves IO throughput from 38MB/s to 42MB/s. The changes in CPU consumption are remarkable. I've looked through the changelogs but cannot find mention of where all that time was being spent? How well have these changes been tested with NFS? The changes are complex and will probably do Bad Things for some people. Does the code implement sufficient debug/reporting/instrumentation to enable you to diagnose, understand and fix people's problems in the minimum possible time? If not, please add that stuff. Just go nuts with it. Put it in debugfs, add /* DELETEME */ comments and we can pull it all out again in half a year or so. Or perhaps litter the code with temporary tracepoints, provided we can come up with a way for our testers to trivially gather their output. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>