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Date: Thu, 06 Dec 2018 11:27:36 +0100
From: Roman Penyaev <rpenyaev@suse.de>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jason Baron <jbaron@akamai.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        akpm@linux-foundation.org
Subject: Re: [RFC PATCH 1/1] epoll: use rwlock in order to reduce
 ep_poll_callback() contention
In-Reply-To: <20181206030818.vu5g3edwl67tg3lc@linux-r8p5>
References: <20181203110237.14787-1-rpenyaev@suse.de>
 <45bce871-edfd-c402-acde-2e57e80cc522@akamai.com>
 <20181206030818.vu5g3edwl67tg3lc@linux-r8p5>
Message-ID: <51d9ca4acbbdb17a390383b839f1aba0@suse.de>
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On 2018-12-06 04:08, Davidlohr Bueso wrote:
>> On 12/3/18 6:02 AM, Roman Penyaev wrote:
> 
>>>  		if (!ep_is_linked(epi)) {
>>> -			list_add_tail(&epi->rdllink, &ep->rdllist);
>>> +			/* Reverse ->ovflist, events should be in FIFO */
>>> +			list_add(&epi->rdllink, &ep->rdllist);
>>>  			ep_pm_stay_awake(epi);
>>>  		}
> 
> This should probably a separate patch as it fixes the ordering,
> regardless of the rwlock+xchg optimization.

Yes, should not be a part of this RFC.  Thanks.

--
Roman