Messages in this thread Patch in this message | | | Date | Sun, 09 Jun 2013 20:30:19 +0800 | From | Chen Gang <> | Subject | [PATCH] kernel/softirq.c: delete 'while' looping to improve a little performance and beautify code |
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After finish the internal 'while', need not test TASKLET_STATE_SCHED again, so looping back to outside 'while' is only for set_bit().
When use 'if' and set_bit() instead of 'while', it will save at least one running conditional instruction, and also will be clearer for readers (although the binary size will be a little bigger).
The related patch is "1da177e Linux-2.6.12-rc2"
Signed-off-by: Chen Gang <gang.chen@asianux.com> --- kernel/softirq.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c index a5f8836..52da25f 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -540,10 +540,11 @@ void tasklet_kill(struct tasklet_struct *t) if (in_interrupt()) printk("Attempt to kill tasklet from interrupt\n"); - while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { + if (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { do { yield(); } while (test_bit(TASKLET_STATE_SCHED, &t->state)); + set_bit(TASKLET_STATE_SCHED, &t->state); } tasklet_unlock_wait(t); clear_bit(TASKLET_STATE_SCHED, &t->state); -- 1.7.7.6
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