From: Michal Hocko <mhocko@kernel.org>
To: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org,
hillf.zj@alibaba-inc.com, minchan@kernel.org,
ying.huang@intel.com, mgorman@techsingularity.net,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
zhong.weidong@zte.com.cn
Subject: Re: [PATCH] mm/vmscan: try to optimize branch procedures.
Date: Tue, 28 Nov 2017 09:03:39 +0100 [thread overview]
Message-ID: <20171128080339.i3ktwm565pz7om4v@dhcp22.suse.cz> (raw)
In-Reply-To: <1511833785-55392-1-git-send-email-jiang.biao2@zte.com.cn>
On Tue 28-11-17 09:49:45, Jiang Biao wrote:
> 1. Use unlikely to try to improve branch prediction. The
> *total_scan < 0* branch is unlikely to reach, so use unlikely.
>
> 2. Optimize *next_deferred >= scanned* condition.
> *next_deferred >= scanned* condition could be optimized into
> *next_deferred > scanned*, because when *next_deferred == scanned*,
> next_deferred shoud be 0, which is covered by the else branch.
>
> 3. Merge two branch blocks into one. The *next_deferred > 0* branch
> could be merged into *next_deferred > scanned* to simplify the code.
How have you measured benefit of this patch?
--
Michal Hocko
SUSE Labs
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next prev parent reply other threads:[~2017-11-28 8:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-28 1:49 Jiang Biao
2017-11-28 8:03 ` Michal Hocko [this message]
2017-11-28 9:19 ` jiang.biao2
2017-11-28 9:31 ` Michal Hocko
2017-11-28 9:46 ` Mel Gorman
2017-11-28 9:40 ` Mel Gorman
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