Re: [PATCH] 2.4 read ahead never reads the last page in a file

[Willy Tarreau]

Hi Chuck,

I've run 2.4.23 both vanilla and patched, and I confirm a win on NFS reads.
I tested from 1 to 6 parallel reads consisting of md5sum of kernel includes :
  time find include -type f | xargs md5sum >/dev/null &
Results below :

processes   2.4.23       2.4.23-patched
    1       11.5         11.45
    2       12.82        12.68
    3       14.7         14.4
    4       17.8         17.3
    5       21.5         21.0
    6       25.7         25.0  => server is saturated 100% sys
    7       29.3         29.0  => server is saturated 100% sys

Fileset contain 7346 files totalizing 29952 kB.
So there's a gain of nearly 3% in the best case (6 processes). Not bad.
I suspect that I could also gain slightly more by patching the server too.

Cheers,
Willy

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