From: Bryan Schumaker Date: Thu, 21 Oct 2010 20:33:18 +0000 (-0400) Subject: NFS: Readdir plus in v4 X-Git-Tag: v2.6.37-rc1~120^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82f2e5472e2304e531c2fa85e457f4a71070044e;p=pandora-kernel.git NFS: Readdir plus in v4 By requsting more attributes during a readdir, we can mimic the readdir plus operation that was in NFSv3. To test, I ran the command `ls -lU --color=none` on directories with various numbers of files. Without readdir plus, I see this: n files | 100 | 1,000 | 10,000 | 100,000 | 1,000,000 --------+-----------+-----------+-----------+-----------+---------- real | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s user | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s sys | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s access | 3 | 1 | 1 | 4 | 31 getattr | 2 | 1 | 1 | 1 | 1 lookup | 104 | 1,003 | 10,003 | 100,003 | 1,000,003 readdir | 2 | 16 | 158 | 1,575 | 15,749 total | 111 | 1,021 | 10,163 | 101,583 | 1,015,784 With readdir plus enabled, I see this: n files | 100 | 1,000 | 10,000 | 100,000 | 1,000,000 --------+-----------+-----------+-----------+-----------+---------- real | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s user | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s sys | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s access | 3 | 1 | 1 | 1 | 7 getattr | 2 | 1 | 1 | 1 | 1 lookup | 4 | 3 | 3 | 3 | 3 readdir | 6 | 62 | 630 | 6,300 | 62,993 total | 15 | 67 | 635 | 6,305 | 63,004 Readdir plus disabled has about a 16x increase in the number of rpc calls and is 4 - 5 times slower on large directories. Signed-off-by: Bryan Schumaker Signed-off-by: Trond Myklebust --- Reading git-diff-tree failed