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From: Joe Perches <joe@perches.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: seq_file optimization?
Date: Fri, 30 Jun 2017 19:48:17 -0700	[thread overview]
Message-ID: <1498877297.2353.10.camel@perches.com> (raw)

About this commit in mm:

---------------------------------------------------
commit c1aca87fb3f84a813fb3dda656bbee583c9c87a3
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date:   Fri Jun 30 11:02:04 2017 +1000

    fs/seq_file.c: delete small-value optimization
    
    num_to_str() optimizes printing small integers [0..9], so the same check
    higher in callchain is unnecessary.
---------------------------------------------------

Is removing this optimization really the same speed?

I don't think so.

The num_to_str call still does multiple moves of
memory to the output, this is a single byte copy.

                 reply	other threads:[~2017-07-01  2:48 UTC|newest]

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