From fce1456a19f5c08b688c29f00ef90fdfa074c79b Mon Sep 17 00:00:00 2001 From: Greg Banks Date: Wed, 4 Oct 2006 02:15:49 -0700 Subject: [PATCH] [PATCH] knfsd: make nfsd readahead params cache SMP-friendly Make the nfsd read-ahead params cache more SMP-friendly by changing the single global list and lock into a fixed 16-bucket hashtable with per-bucket locks. This reduces spinlock contention in nfsd_read() on read-heavy workloads on multiprocessor servers. Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients each doing 1K streaming reads at full line rate. The server had 128 nfsd threads, which sizes the RA cache at 256 entries, of which only a handful were used. Flat profiling shows nfsd_read(), including the inlined nfsd_get_raparms(), taking 10.4% of each CPU. This patch drops the contribution from nfsd() to 1.71% for each CPU. Signed-off-by: Greg Banks Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed