From: Johannes Berg <johannes@sipsolutions.net>
To: Rakesh Pillai <pillair@codeaurora.org>, ath10k@lists.infradead.org
Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org,
netdev@vger.kernel.org, dianders@chromium.org,
evgreen@chromium.org
Subject: Re: [RFC 1/7] mac80211: Add check for napi handle before WARN_ON
Date: Thu, 23 Jul 2020 22:06:46 +0200 [thread overview]
Message-ID: <ce380ea1fd1f5db40a92f67673f070a1f88eee50.camel@sipsolutions.net> (raw)
In-Reply-To: <003201d6611e$c54a1c90$4fde55b0$@codeaurora.org>
On Thu, 2020-07-23 at 23:56 +0530, Rakesh Pillai wrote:
> > > - WARN_ON_ONCE(softirq_count() == 0);
> > > + WARN_ON_ONCE(napi && softirq_count() == 0);
> >
> > FWIW, I'm pretty sure this is incorrect - we make assumptions on
> > softirqs being disabled in mac80211 for serialization and in place of
> > some locking, I believe.
> >
>
> I checked this, but let me double confirm.
> But after this change, no packet is submitted from driver in a softirq context.
> So ideally this should take care of serialization.
I'd guess that we have some reliance on BHs already being disabled, for
things like u64 sync updates, or whatnot. I mean, we did "rx_ni()" for a
reason ... Maybe lockdep can help catch some of the issues.
But couldn't you be in a thread and have BHs disabled too?
johannes
next prev parent reply other threads:[~2020-07-23 20:07 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 17:14 [RFC 0/7] Add support to process rx packets in thread Rakesh Pillai
2020-07-21 17:14 ` [RFC 1/7] mac80211: Add check for napi handle before WARN_ON Rakesh Pillai
2020-07-22 12:56 ` Johannes Berg
2020-07-23 18:26 ` Rakesh Pillai
2020-07-23 20:06 ` Johannes Berg [this message]
2020-07-24 6:21 ` Rakesh Pillai
2020-07-26 16:19 ` Rakesh Pillai
2020-07-30 12:40 ` Johannes Berg
2020-07-21 17:14 ` [RFC 2/7] ath10k: Add support to process rx packet in thread Rakesh Pillai
2020-07-21 21:53 ` Rajkumar Manoharan
2020-07-22 12:27 ` Felix Fietkau
2020-07-22 12:55 ` Johannes Berg
2020-07-22 13:00 ` Felix Fietkau
2020-07-23 6:09 ` Rajkumar Manoharan
2021-03-22 23:57 ` Ben Greear
2021-03-23 1:20 ` Brian Norris
2021-03-23 3:01 ` Ben Greear
2021-03-23 7:45 ` Felix Fietkau
2021-03-25 9:45 ` Rakesh Pillai
2021-03-25 10:33 ` Felix Fietkau
2020-07-23 18:25 ` Rakesh Pillai
2020-07-24 23:11 ` Jacob Keller
2020-07-21 17:14 ` [RFC 3/7] ath10k: Add module param to enable rx thread Rakesh Pillai
2020-07-21 17:14 ` [RFC 4/7] ath10k: Do not exhaust budget on process tx completion Rakesh Pillai
2020-07-21 17:14 ` [RFC 5/7] ath10k: Handle the rx packet processing in thread Rakesh Pillai
2020-07-21 17:14 ` [RFC 6/7] ath10k: Add deliver to stack from thread context Rakesh Pillai
2020-07-21 17:14 ` [RFC 7/7] ath10k: Handle rx thread suspend and resume Rakesh Pillai
2020-07-23 23:06 ` Sebastian Gottschall
2020-07-24 6:19 ` Rakesh Pillai
2020-07-21 17:25 ` [RFC 0/7] Add support to process rx packets in thread Andrew Lunn
2020-07-21 18:05 ` Florian Fainelli
2020-07-23 18:21 ` Rakesh Pillai
2020-07-23 19:02 ` Florian Fainelli
2020-07-24 6:20 ` Rakesh Pillai
2020-07-24 22:28 ` Florian Fainelli
2020-07-22 9:12 ` David Laight
2020-07-22 16:20 ` Jakub Kicinski
[not found] ` <20200725081633.7432-1-hdanton@sina.com>
2020-07-25 10:38 ` Sebastian Gottschall
2020-07-25 14:08 ` Sebastian Gottschall
[not found] ` <20200725145728.10556-1-hdanton@sina.com>
2020-07-25 15:41 ` Sebastian Gottschall
2020-07-26 11:16 ` David Laight
2020-07-28 16:59 ` Rakesh Pillai
2020-07-25 17:57 ` Felix Fietkau
[not found] ` <20200726012244.15264-1-hdanton@sina.com>
2020-07-26 8:10 ` Felix Fietkau
[not found] ` <20200726083239.5060-1-hdanton@sina.com>
2020-07-26 8:59 ` Felix Fietkau
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