hi about process_backlog()

[Vignesh Radhakrishnan]

Hi,

I was tracing the program flow. So basically i figured out that
net_rx_action calls process_backlog and i saw that deletion is happening at
net_rx_action().

So i used git blame on that file and saw that this commit performed the
deletion. Then when i saw what the commit does, i found that it changed the
deletion location from process_backlog to here.

Thanks and regards,
Vignesh Radhakrishnan

On Wed, Dec 24, 2014 at 8:22 AM, lx <lxgeek at yahoo.com> wrote:

> hi :
>     How to find this commit:
> #################################
> Earlier we had deletion in process_backlog itself, but
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/
> linux.git/commit/?id=d75b1ade567ffab085e8adbbdacf0092d10cd09c has changed
> it.
> #################################
>
> There are so many commits, and this commit don't show some messages about
> process_backlog().The messages is:
> #################################
> commit d75b1ade567ffab085e8adbbdacf0092d10cd09c
> Author: Eric Dumazet <edumazet at google.com>
> Date:   Sun Nov 2 06:19:33 2014 -0800
>
>     net: less interrupt masking in NAPI
>
>     net_rx_action() can mask irqs a single time to transfert sd->poll_list
>     into a private list, for a very short duration.
>
>     Then, napi_complete() can avoid masking irqs again,
>     and net_rx_action() only needs to mask irq again in slow path.
>
>     This patch removes 2 couples of irq mask/unmask per typical NAPI run,
>     more if multiple napi were triggered.
>
>     Note this also allows to give control back to caller (do_softirq())
>     more often, so that other softirq handlers can be called a bit earlier,
>     or ksoftirqd can be wakeup earlier under pressure.
>
>     This was developed while testing an alternative to RX interrupt
>     mitigation to reduce latencies while keeping or improving GRO
>     aggregation on fast NIC.
>
>     Idea is to test napi->gro_list at the end of a napi->poll() and
>     reschedule one NAPI poll, but after servicing a full round of
>     softirqs (timers, TX, rcu, ...). This will be allowed only if softirq
>     is currently serviced by idle task or ksoftirqd, and resched not
> needed.
>
>     Signed-off-by: Eric Dumazet <edumazet at google.com>
>     Cc: Willem de Bruijn <willemb at google.com>
>     Signed-off-by: David S. Miller <davem at davemloft.net>
> #################################
>
>
> Thank you.
>



-- 
http://vigneshradhakrishnan.blogspot.com/
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