From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 9385E6B0038 for ; Thu, 21 Dec 2017 22:18:26 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id 207so9543652iti.5 for ; Thu, 21 Dec 2017 19:18:26 -0800 (PST) Received: from aserp2130.oracle.com (aserp2130.oracle.com. [141.146.126.79]) by mx.google.com with ESMTPS id e2si6010120itf.115.2017.12.21.19.18.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Dec 2017 19:18:25 -0800 (PST) Subject: Re: [PATCH] Move kfree_call_rcu() to slab_common.c References: <1513844387-2668-1-git-send-email-rao.shoaib@oracle.com> <20171221123630.GB22405@bombadil.infradead.org> <44044955-1ef9-1d1e-5311-d8edc006b812@oracle.com> <20171222013937.GA7829@linux.vnet.ibm.com> From: Rao Shoaib Message-ID: <106f9cdb-bb0b-539d-547e-18c509ca1163@oracle.com> Date: Thu, 21 Dec 2017 19:17:35 -0800 MIME-Version: 1.0 In-Reply-To: <20171222013937.GA7829@linux.vnet.ibm.com> Content-Type: multipart/alternative; boundary="------------59C28A6D52A0CCD0686C9CAF" Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: paulmck@linux.vnet.ibm.com Cc: Matthew Wilcox , linux-kernel@vger.kernel.org, brouer@redhat.com, linux-mm@kvack.org This is a multi-part message in MIME format. --------------59C28A6D52A0CCD0686C9CAF Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit On 12/21/2017 05:39 PM, Paul E. McKenney wrote: >> I left it out on purpose because the call in tiny is a little different >> >> rcutiny.h: >> >> static inline void kfree_call_rcu(struct rcu_head *head, >> A A A A A A A A A A A A A void (*func)(struct rcu_head *rcu)) >> { >> A A A call_rcu(head, func); >> } >> >> tree.c: >> >> void kfree_call_rcu(struct rcu_head *head, >> A A A A A A A A A void (*func)(struct rcu_head *rcu)) >> { >> A A A __call_rcu(head, func, rcu_state_p, -1, 1); >> } >> EXPORT_SYMBOL_GPL(kfree_call_rcu); >> >> If we want the code to be exactly same I can create a lazy version >> for tiny as well. However,A I don not know where to move >> kfree_call_rcu() from it's current home in rcutiny.h though. Any >> thoughts ? > I might be missing something subtle here, but in case I am not, my > suggestion is to simply rename rcutiny.h's kfree_call_rcu() and otherwise > leave it as is. If you want to update the type of the second argument, > which got missed back in the day, there is always this: > > static inline void call_rcu_lazy(struct rcu_head *head, rcu_callback_t func) > { > call_rcu(head, func); > } > > The reason that Tiny RCU doesn't handle laziness specially is because > Tree RCU's handling of laziness is a big no-op on the single CPU systems > on which Tiny RCU runs. So Tiny RCU need do nothing special to support > laziness. > > Thanx, Paul > Hi Paul, I can not just change the name as __kfree_call_rcu macro calls kfree_call_rcu(). I have made tiny version of kfree_call_rcu() call rcu_call_lazy() which calls call_rcu(). As far as the type is concerned, my bad, I cut and posted from an older release. Latest code is already using the typedef. Shoaib --------------59C28A6D52A0CCD0686C9CAF Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit

On 12/21/2017 05:39 PM, Paul E. McKenney wrote:

I left it out on purpose because the call in tiny is a little different

rcutiny.h:

static inline void kfree_call_rcu(struct rcu_head *head,
A A A  A A A  A A A  A A A  A  void (*func)(struct rcu_head *rcu))
{
A A A  call_rcu(head, func);
}

tree.c:

void kfree_call_rcu(struct rcu_head *head,
A A A  A A A  A A A  void (*func)(struct rcu_head *rcu))
{
A A A  __call_rcu(head, func, rcu_state_p, -1, 1);
}
EXPORT_SYMBOL_GPL(kfree_call_rcu);

If we want the code to be exactly same I can create a lazy version
for tiny as well. However,A  I don not know where to move
kfree_call_rcu() from it's current home in rcutiny.h though. Any
thoughts ?

I might be missing something subtle here, but in case I am not, my
suggestion is to simply rename rcutiny.h's kfree_call_rcu() and otherwise
leave it as is.  If you want to update the type of the second argument,
which got missed back in the day, there is always this:

static inline void call_rcu_lazy(struct rcu_head *head, rcu_callback_t func)
{
	call_rcu(head, func);
}

The reason that Tiny RCU doesn't handle laziness specially is because
Tree RCU's handling of laziness is a big no-op on the single CPU systems
on which Tiny RCU runs.  So Tiny RCU need do nothing special to support
laziness.

							Thanx, Paul

Hi Paul,

I can not just change the name as __kfree_call_rcu macro calls kfree_call_rcu(). I have made tiny version of kfree_call_rcu() call rcu_call_lazy() which calls call_rcu(). As far as the type is concerned, my bad, I cut and posted from an older release. Latest code is already using the typedef.

Shoaib
--------------59C28A6D52A0CCD0686C9CAF-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org