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From: Joel Fernandes <joel@joelfernandes.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Ingo Molnar <mingo@redhat.com>, Jonathan Corbet <corbet@lwn.net>,
	Josh Triplett <josh@joshtriplett.org>,
	kvm-ppc@vger.kernel.org, Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	"Paul E. McKenney" <paulmck@linux.ibm.com>,
	Paul Mackerras <paulus@ozlabs.org>,
	rcu@vger.kernel.org
Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs
Date: Sat, 25 May 2019 08:14:44 +0000	[thread overview]
Message-ID: <20190525081444.GC197789@google.com> (raw)
In-Reply-To: <20190524232458.4bcf4eb4@gandalf.local.home>

On Fri, May 24, 2019 at 11:24:58PM -0400, Steven Rostedt wrote:
> On Fri, 24 May 2019 19:49:28 -0400
> "Joel Fernandes (Google)" <joel@joelfernandes.org> wrote:
> 
> > The series removes users of the following APIs, and the APIs themselves, since
> > the regular non - _notrace variants don't do any tracing anyway.
> >  * hlist_for_each_entry_rcu_notrace
> >  * rcu_dereference_raw_notrace
> > 
> 
> I guess the difference between the _raw_notrace and just _raw variants
> is that _notrace ones do a rcu_check_sparse(). Don't we want to keep
> that check?

This is true.

Since the users of _raw_notrace are very few, is it worth keeping this API
just for sparse checking? The API naming is also confusing. I was expecting
_raw_notrace to do fewer checks than _raw, instead of more. Honestly, I just
want to nuke _raw_notrace as done in this series and later we can introduce a
sparse checking version of _raw if need-be. The other option could be to
always do sparse checking for _raw however that used to be the case and got
changed in http://lists.infradead.org/pipermail/linux-afs/2016-July/001016.html

thanks a lot,

 - Joel

> 
> -- Steve

WARNING: multiple messages have this Message-ID (diff)
From: Joel Fernandes <joel@joelfernandes.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Ingo Molnar <mingo@redhat.com>, Jonathan Corbet <corbet@lwn.net>,
	Josh Triplett <josh@joshtriplett.org>,
	kvm-ppc@vger.kernel.org, Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	"Paul E. McKenney" <paulmck@linux.ibm.com>,
	Paul Mackerras <paulus@ozlabs.org>,
	rcu@vger.kernel.org
Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs
Date: Sat, 25 May 2019 04:14:44 -0400	[thread overview]
Message-ID: <20190525081444.GC197789@google.com> (raw)
In-Reply-To: <20190524232458.4bcf4eb4@gandalf.local.home>

On Fri, May 24, 2019 at 11:24:58PM -0400, Steven Rostedt wrote:
> On Fri, 24 May 2019 19:49:28 -0400
> "Joel Fernandes (Google)" <joel@joelfernandes.org> wrote:
> 
> > The series removes users of the following APIs, and the APIs themselves, since
> > the regular non - _notrace variants don't do any tracing anyway.
> >  * hlist_for_each_entry_rcu_notrace
> >  * rcu_dereference_raw_notrace
> > 
> 
> I guess the difference between the _raw_notrace and just _raw variants
> is that _notrace ones do a rcu_check_sparse(). Don't we want to keep
> that check?

This is true.

Since the users of _raw_notrace are very few, is it worth keeping this API
just for sparse checking? The API naming is also confusing. I was expecting
_raw_notrace to do fewer checks than _raw, instead of more. Honestly, I just
want to nuke _raw_notrace as done in this series and later we can introduce a
sparse checking version of _raw if need-be. The other option could be to
always do sparse checking for _raw however that used to be the case and got
changed in http://lists.infradead.org/pipermail/linux-afs/2016-July/001016.html

thanks a lot,

 - Joel

> 
> -- Steve

WARNING: multiple messages have this Message-ID (diff)
From: Joel Fernandes <joel@joelfernandes.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: rcu@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
	linux-doc@vger.kernel.org, Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org,
	Josh Triplett <josh@joshtriplett.org>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Ingo Molnar <mingo@redhat.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	"Paul E. McKenney" <paulmck@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH RFC 0/5] Remove some notrace RCU APIs
Date: Sat, 25 May 2019 04:14:44 -0400	[thread overview]
Message-ID: <20190525081444.GC197789@google.com> (raw)
In-Reply-To: <20190524232458.4bcf4eb4@gandalf.local.home>

On Fri, May 24, 2019 at 11:24:58PM -0400, Steven Rostedt wrote:
> On Fri, 24 May 2019 19:49:28 -0400
> "Joel Fernandes (Google)" <joel@joelfernandes.org> wrote:
> 
> > The series removes users of the following APIs, and the APIs themselves, since
> > the regular non - _notrace variants don't do any tracing anyway.
> >  * hlist_for_each_entry_rcu_notrace
> >  * rcu_dereference_raw_notrace
> > 
> 
> I guess the difference between the _raw_notrace and just _raw variants
> is that _notrace ones do a rcu_check_sparse(). Don't we want to keep
> that check?

This is true.

Since the users of _raw_notrace are very few, is it worth keeping this API
just for sparse checking? The API naming is also confusing. I was expecting
_raw_notrace to do fewer checks than _raw, instead of more. Honestly, I just
want to nuke _raw_notrace as done in this series and later we can introduce a
sparse checking version of _raw if need-be. The other option could be to
always do sparse checking for _raw however that used to be the case and got
changed in http://lists.infradead.org/pipermail/linux-afs/2016-July/001016.html

thanks a lot,

 - Joel

> 
> -- Steve

  reply	other threads:[~2019-05-25  8:14 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-24 23:49 [PATCH RFC 0/5] Remove some notrace RCU APIs Joel Fernandes (Google)
2019-05-24 23:49 ` Joel Fernandes (Google)
2019-05-24 23:49 ` Joel Fernandes (Google)
2019-05-24 23:49 ` [PATCH RFC 1/5] powerpc: Use regular rcu_dereference_raw API Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49 ` [PATCH RFC 2/5] trace: " Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49 ` [PATCH RFC 3/5] hashtable: Use the regular hlist_for_each_entry_rcu API Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49 ` [PATCH RFC 4/5] rculist: Remove hlist_for_each_entry_rcu_notrace since no users Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-26 16:20   ` Miguel Ojeda
2019-05-26 16:20     ` Miguel Ojeda
2019-05-26 16:20     ` Miguel Ojeda
2019-05-24 23:49 ` [PATCH RFC 5/5] rcu: Remove rcu_dereference_raw_notrace " Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-24 23:49   ` Joel Fernandes (Google)
2019-05-25  3:24 ` [PATCH RFC 0/5] Remove some notrace RCU APIs Steven Rostedt
2019-05-25  3:24   ` Steven Rostedt
2019-05-25  3:24   ` Steven Rostedt
2019-05-25  8:14   ` Joel Fernandes [this message]
2019-05-25  8:14     ` Joel Fernandes
2019-05-25  8:14     ` Joel Fernandes
2019-05-25 11:08     ` Steven Rostedt
2019-05-25 11:08       ` Steven Rostedt
2019-05-25 11:08       ` Steven Rostedt
2019-05-25 14:19       ` Joel Fernandes
2019-05-25 14:19         ` Joel Fernandes
2019-05-25 14:19         ` Joel Fernandes
2019-05-25 15:50         ` Paul E. McKenney
2019-05-25 15:50           ` Paul E. McKenney
2019-05-25 15:50           ` Paul E. McKenney
2019-05-25 18:14           ` Joel Fernandes
2019-05-25 18:14             ` Joel Fernandes
2019-05-25 18:14             ` Joel Fernandes
2019-05-25 18:18             ` Joel Fernandes
2019-05-25 18:18               ` Joel Fernandes
2019-05-25 18:18               ` Joel Fernandes
2019-05-28 12:24             ` Paul E. McKenney
2019-05-28 12:24               ` Paul E. McKenney
2019-05-28 12:24               ` Paul E. McKenney
2019-05-28 19:00               ` Joel Fernandes
2019-05-28 19:00                 ` Joel Fernandes
2019-05-28 19:00                 ` Joel Fernandes
2019-05-28 20:00                 ` Paul E. McKenney
2019-05-28 20:00                   ` Paul E. McKenney
2019-05-28 20:00                   ` Paul E. McKenney

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