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From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Amol Grover <frextrite@gmail.com>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	"Paul E. McKenney" <paulmck@kernel.org>
Subject: Re: [PATCH 1/2] drivers: base: power: main: Use built-in RCU list checking
Date: Mon, 2 Mar 2020 18:02:21 +0100	[thread overview]
Message-ID: <CAJZ5v0hee4FxeVub_ZkAYn9z8q1_ZLA_AcmTtS-w39VzSe0UxA@mail.gmail.com> (raw)
In-Reply-To: <CAD=jOEZ3vdNC4qTMxptaXLjs7i8TCTYjeiv9vXhcapLSkrr9RQ@mail.gmail.com>

On Mon, Mar 2, 2020 at 1:34 PM Madhuparna Bhowmik
<madhuparnabhowmik10@gmail.com> wrote:
>
>
>
> On Mon, 2 Mar, 2020, 3:48 AM Joel Fernandes, <joel@joelfernandes.org> wrote:
>>
>> On Sun, Mar 1, 2020 at 4:23 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>> >
>> > On Sun, Mar 1, 2020 at 9:53 PM <joel@joelfernandes.org> wrote:
>> > >
>> > >
>> > >
>> > > On March 1, 2020 3:12:53 PM EST, "Rafael J. Wysocki" <rafael@kernel.org> wrote:
>> > > >On Fri, Feb 28, 2020 at 6:47 PM <madhuparnabhowmik10@gmail.com> wrote:
>> > > >>
>> > > >> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>> > > >>
>> > > >> This patch passes the cond argument to list_for_each_entry_rcu()
>> > > >> to fix the following false-positive lockdep warnings:
>> > > >>
>> > > >> [  330.302784] =============================
>> > > >> [  330.302789] WARNING: suspicious RCU usage
>> > > >> [  330.302796] 5.6.0-rc1+ #5 Not tainted
>> > > >> [  330.302801] -----------------------------
>> > > >> [  330.302808] drivers/base/power/main.c:326 RCU-list traversed in
>> > > >non-reader section!!
>> > > >>
>> > > >> [  330.303303] =============================
>> > > >> [  330.303307] WARNING: suspicious RCU usage
>> > > >> [  330.303311] 5.6.0-rc1+ #5 Not tainted
>> > > >> [  330.303315] -----------------------------
>> > > >> [  330.303319] drivers/base/power/main.c:1698 RCU-list traversed in
>> > > >non-reader section!!
>> > > >>
>> > > >> [  331.934969] =============================
>> > > >> [  331.934971] WARNING: suspicious RCU usage
>> > > >> [  331.934973] 5.6.0-rc1+ #5 Not tainted
>> > > >> [  331.934975] -----------------------------
>> > > >> [  331.934977] drivers/base/power/main.c:1238 RCU-list traversed in
>> > > >non-reader section!!
>> > > >>
>> > > >> [  332.467772] WARNING: suspicious RCU usage
>> > > >> [  332.467775] 5.6.0-rc1+ #5 Not tainted
>> > > >> [  332.467775] -----------------------------
>> > > >> [  332.467778] drivers/base/power/main.c:269 RCU-list traversed in
>> > > >non-reader section!!
>> > > >
>> > > >I don't see these warnings in the kernels run locally here.
>> > > >
>> > > >What do you do to get them?
>> > > >
>> > > >Joel, any comments here?
>> > >
>> > > You have to enable lockdep in your config. Does your setup have that?
>> >
>> > CONFIG_LOCK_DEBUGGING_SUPPORT=y
>> > CONFIG_PROVE_LOCKING=y
>> > CONFIG_DEBUG_SPINLOCK=y
>> > CONFIG_DEBUG_LOCK_ALLOC=y
>> > CONFIG_LOCKDEP=y
>>
>>
> I had CONFIG_PROVE_RCU_LIST = y and I think these warnings were triggered when I had closed my laptop (like just close without shutting down).

OK, so let's define a macro for that in this file to avoid code duplication.

And analogously in the second patch.

Thanks!

  parent reply	other threads:[~2020-03-02 17:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-28 17:46 [PATCH 1/2] drivers: base: power: main: Use built-in RCU list checking madhuparnabhowmik10
2020-03-01 20:12 ` Rafael J. Wysocki
2020-03-01 20:53   ` joel
2020-03-01 21:23     ` Rafael J. Wysocki
2020-03-01 22:18       ` Joel Fernandes
     [not found]         ` <CAD=jOEZ3vdNC4qTMxptaXLjs7i8TCTYjeiv9vXhcapLSkrr9RQ@mail.gmail.com>
2020-03-02 17:02           ` Rafael J. Wysocki [this message]
2020-03-03 16:09             ` Madhuparna Bhowmik

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