diff options
author | Oleg Nesterov <oleg@tv-sign.ru> | 2006-12-06 20:36:54 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 08:39:34 -0800 |
commit | 51de4d90852ba4cfa5743594ec4a7f158b52dc43 (patch) | |
tree | 27ee40313c79c3c5fa2ef86fc059cf991c92e8e2 /kernel/seccomp.c | |
parent | 68062b86fc0f480b806d270a8278709a5a41bb67 (diff) |
[PATCH] taskstats: use nla_reserve() for reply assembling
Currently taskstats_user_cmd()/taskstats_exit() do:
1) allocate stats
2) fill stats
3) make a temporary copy on stack (236 bytes)
4) copy that copy to skb
5) free stats
With the help of nla_reserve() we can operate on skb->data directly,
thus avoiding all these steps except 2).
So, before this patch:
// copy *stats to skb->data
int mk_reply(skb, ..., struct taskstats *stats);
fill_pid(stats);
mk_reply(skb, ..., stats);
After:
// return a pointer to skb->data
struct taskstats *mk_reply(skb, ...);
stat = mk_reply(skb, ...);
fill_pid(stats);
Shrinks taskatsks.o by 162 bytes.
A stupid benchmark (send one million TASKSTATS_CMD_ATTR_PID) shows the
real user sys
before:
4.02 0.06 3.96
4.02 0.04 3.98
4.02 0.04 3.97
after:
3.86 0.08 3.78
3.88 0.10 3.77
3.89 0.09 3.80
but this looks suspiciously good.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/seccomp.c')
0 files changed, 0 insertions, 0 deletions