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| author | Eric Dumazet <[email protected]> | 2012-03-23 22:02:53 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2012-03-23 23:58:42 +0000 |
| commit | 59a32e2ce5eb809967cac4e718bc527beca83c59 (patch) | |
| tree | 3024b71063f497c138680c36c5f7ce2dee563680 /fs/proc/array.c | |
| parent | fs/proc/kcore.c: make get_sparsemem_vmemmap_info() static (diff) | |
| download | kernel-59a32e2ce5eb809967cac4e718bc527beca83c59.tar.gz kernel-59a32e2ce5eb809967cac4e718bc527beca83c59.zip | |
proc: speed up /proc/stat handling
On a typical 16 cpus machine, "cat /proc/stat" gives more than 4096 bytes,
and is slow :
# strace -T -o /tmp/STRACE cat /proc/stat | wc -c
5826
# grep "cpu " /tmp/STRACE
read(0, "cpu 1949310 19 2144714 12117253"..., 32768) = 5826 <0.001504>
Thats partly because show_stat() must be called twice since initial
buffer size is too small (4096 bytes for less than 32 possible cpus)
Fix this by :
1) Taking into account nr_irqs in the initial buffer sizing.
2) Using ksize() to allow better filling of initial buffer.
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Glauber Costa <[email protected]>
Cc: Russell King - ARM Linux <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'fs/proc/array.c')
0 files changed, 0 insertions, 0 deletions