The patch titled Subject: proc: speed up /proc/stat handling has been removed from the -mm tree. Its filename was proc-speedup-proc-stat-handling.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ From: Eric Dumazet <eric.dumazet@xxxxxxxxx> Subject: 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 <eric.dumazet@xxxxxxxxx> Cc: Glauber Costa <glommer@xxxxxxxxxxxxx> Cc: Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Paul Turner <pjt@xxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/stat.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff -puN fs/proc/stat.c~proc-speedup-proc-stat-handling fs/proc/stat.c --- a/fs/proc/stat.c~proc-speedup-proc-stat-handling +++ a/fs/proc/stat.c @@ -157,11 +157,14 @@ static int show_stat(struct seq_file *p, static int stat_open(struct inode *inode, struct file *file) { - unsigned size = 4096 * (1 + num_possible_cpus() / 32); + unsigned size = 1024 + 128 * num_possible_cpus(); char *buf; struct seq_file *m; int res; + /* minimum size to display an interrupt count : 2 bytes */ + size += 2 * nr_irqs; + /* don't ask for more than the kmalloc() max size */ if (size > KMALLOC_MAX_SIZE) size = KMALLOC_MAX_SIZE; @@ -173,7 +176,7 @@ static int stat_open(struct inode *inode if (!res) { m = file->private_data; m->buf = buf; - m->size = size; + m->size = ksize(buf); } else kfree(buf); return res; _ Patches currently in -mm which might be from eric.dumazet@xxxxxxxxx are origin.patch linux-next.patch net-use-this_cpu_xxx-replace-percpu_xxx-funcs.patch lib-cpumaskc-remove-__any_online_cpu.patch syscalls-x86-add-__nr_kcmp-syscall-v8.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html