Re: [RFC 7/7] net: don't check for active hrtimer after adding it

From: Chris Redpath
Date: Wed Jul 09 2014 - 06:48:24 EST

On 09/07/14 11:44, Viresh Kumar wrote:
Hi Chris,

On 9 July 2014 16:02, Chris Redpath <Chris.Redpath@xxxxxxx> wrote:

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index fc17a9d..f911acd 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2186,8 +2186,6 @@ static void spin(struct pktgen_dev *pkt_dev, ktime_t
do {
hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
- if (!hrtimer_active(&t.timer))
- t.task = NULL;

if (likely(t.task))

I think this if condition can also be removed. hrtimer_init_sleeper copies
the supplied task_struct * to the timer, which in this case is 'current'.
The check is likely to be there in case of !active case you removed.

Yeah, it looks like we can get rid of this. Also,

} while (t.task && pkt_dev->running && !signal_pending(current));

is present in the closing "}" of do-while loop and probably we
don't need to check t.task here as well.

And this review comment applies to patch 2/7 as well:
hrtimer: don't check for active hrtimer after adding it

I would still wait for somebody to prove us wrong :), and will resend
it next week only.


Yeah, no worries. I just happened to read it and not knowing any of the APIs had to look up what is going on.

BTW, I *will* get back to you about that broadcast stuff when I get back to it myself. Other priorities at the moment again.

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