All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Marc Kleine-Budde <mkl@pengutronix.de>, linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH RFC v2 1/2] can: fix multiple delivery of a single CAN frame for overlapping CAN filters
Date: Tue, 31 Mar 2015 22:24:20 +0200	[thread overview]
Message-ID: <551B0274.1010900@hartkopp.net> (raw)
In-Reply-To: <551A93D0.6000302@pengutronix.de>

On 31.03.2015 14:32, Marc Kleine-Budde wrote:
> On 03/30/2015 12:41 PM, Oliver Hartkopp wrote:
>> Please check out
>>
>> https://www.kernel.org/pub/linux/kernel/people/rusty/kernel-locking/
>>
>> And especially
>> https://www.kernel.org/pub/linux/kernel/people/rusty/kernel-locking/x173.html#LOCK-SOFTIRQS-SAME
>>
>> When a softirq processes an incoming skb this remains on that selected CPU.
>
> Okay, I was not sure about this. What about preempt_rt?
>

I don't care :-)

There are so many implementations that rely on this per-CPU stuff that we can 
assume preempt_rt takes care of it (e.g. with locking or reducing CPU cores, etc)

>> Putting a struct into these percpu handling can be done - but does it increase
>> the readability in this case?
>
> It saves ressources, 1 pointer instead of 3 (considering both of your
> patches) and only 1 allocation.

Yes. I did some more code reading, created a struct for it and omitted the 
initialization as alloc_percpu returns an already zero'ed memory region.

Will send tomorrow morning.

Regards,
Oliver

  reply	other threads:[~2015-03-31 20:24 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-29 18:09 [PATCH RFC v2 0/2] can: join filters with per-CPU variables Oliver Hartkopp
2015-03-29 18:09 ` [PATCH RFC v2 1/2] can: fix multiple delivery of a single CAN frame for overlapping CAN filters Oliver Hartkopp
2015-03-30  9:50   ` Marc Kleine-Budde
2015-03-30 10:29     ` Oliver Hartkopp
2015-03-30 10:36       ` Marc Kleine-Budde
2015-03-30 10:10   ` Marc Kleine-Budde
2015-03-30 10:16     ` Marc Kleine-Budde
2015-03-30 10:41     ` Oliver Hartkopp
2015-03-31 12:32       ` Marc Kleine-Budde
2015-03-31 20:24         ` Oliver Hartkopp [this message]
2015-03-30 12:33   ` Sergei Shtylyov
2015-03-30 15:49     ` Oliver Hartkopp
2015-03-30 17:14       ` Sergei Shtylyov
2015-03-30 17:25         ` Oliver Hartkopp
2015-03-29 18:09 ` [PATCH RFC v2 2/2] can: introduce new raw socket option to join the given " Oliver Hartkopp
2015-03-31 12:36   ` Marc Kleine-Budde
2015-03-31 20:30     ` Oliver Hartkopp

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=551B0274.1010900@hartkopp.net \
    --to=socketcan@hartkopp.net \
    --cc=linux-can@vger.kernel.org \
    --cc=mkl@pengutronix.de \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.