linux-kernel - Re: seq_file: Use larger buffer to reduce time traversing lists

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Date:	Fri, 01 Jun 2012 17:47:45 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Steven Whitehouse <swhiteho@...hat.com>
Cc:	linux-kernel@...r.kernel.org, cluster-devel@...hat.com,
	Al Viro <viro@...iv.linux.org.uk>, nstraz@...hat.com
Subject: Re: seq_file: Use larger buffer to reduce time traversing lists

On Fri, 2012-06-01 at 16:28 +0100, Steven Whitehouse wrote:

> I'll certainly have a look at the hash table based approach too.

This is the reasonable approach, because most seq_file users do :

cat /path | ...

FILE *F = fopen("/path", "r");

ie they use small read size (<= 32 KB)

NOWARN can still slow down the whole machine.

You apparently don't have machines with fragmented memory...

hint : __GFP_NORETRY & PAGE_ALLOC_COSTLY_ORDER







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