Hi Bruce, On Sat, Oct 14, 2006 at 07:25:12AM +0000, Bruce Evans wrote: > bde 2006-10-14 07:25:12 UTC > > FreeBSD src repository > > Modified files: > sys/nfsclient nfs_vnops.c > Log: > Don't do null Setattr RPCs for VA_MARK_ATIME. When we added the > VA_MARK_ATIME feature to fix POSIX conformance fore execve() and mmap(), > we thought that it was optimized well enough for the one file system > that supports it (ffs) and harmless for other file systems (except > layered ones which already get the layering for VOP_SETATTR() wrong). > However, nfs_setattr() doesn't do much parameter checking, so when > it gets a combination of parameters that it doesn't understand, it > always does a Setattr RPC. This RPC can't do anything good, and for > VA_MARK_ATIME it is null except for wasting a lot of time. > > This is the smallest and easiest to fix of several bugs that have > increased the number of RPCs for kernel builds on nfs by more than > 100% since 2004-11-05. The real-time increase depends on network > latency and parallelization and can also be very large (approaching > the same percentage for unparallelized operations like "make depend" > on systems with fast CPUs and high-latency networks). > > Revision Changes Path > 1.270 +2 -2 src/sys/nfsclient/nfs_vnops.c
The code in RELENG_6 looks as if it would benefit from this change as well. Do you have a MFC planned in the nearby future? -- Rink P.W. Springer - http://rink.nu "Patience is for those who cannot afford decent hardware." - Peter Koeleman
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