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From: Andi Kleen <andi@firstfloor.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] proc: faster /proc/*/status
Date: Sat, 06 Aug 2016 20:16:27 -0700	[thread overview]
Message-ID: <87ziop46b8.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <20160806125608.GB1187@p183.telecom.by> (Alexey Dobriyan's message of "Sat, 6 Aug 2016 15:56:11 +0300")

Alexey Dobriyan <adobriyan@gmail.com> writes:
> -
> +	seq_printf(m, "State:\t%s", get_task_state(p));
> +
> +	seq_puts(m, "\nTgid:\t");

The only different should be the format string.

Scanning the format string really shouldn't be that expensive?!?

It would be better if you could find out why that is slow and optimize
it. Then you would benefit every seq_printf user, not just this
special case.

Perhaps it could benefit from some of the bit masking tricks to
scan the string with wider tests than a word.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only

  parent reply	other threads:[~2016-08-07  3:16 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-06 12:56 [PATCH] proc: faster /proc/*/status Alexey Dobriyan
2016-08-06 22:41 ` Joe Perches
2016-08-09  3:02   ` [PATCH] seq/proc: Modify seq_put_decimal_[u]ll to take a const char *, not char Joe Perches
2016-08-07  3:16 ` Andi Kleen [this message]
2016-08-07  8:53   ` [PATCH] proc: faster /proc/*/status Alexey Dobriyan
2016-08-07 16:59     ` Andi Kleen
2016-08-07 17:39       ` Joe Perches
2016-08-07 17:44         ` Andi Kleen
2016-08-07 21:22           ` Joe Perches
2016-08-09 23:25             ` Andrew Morton
2016-08-10  6:38               ` [RFC PATCH] meminfo: Break apart a very long seq_printf with #ifdefs Joe Perches
2016-08-11 21:50                 ` Andrew Morton
2016-08-11 21:57                   ` Joe Perches

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