From mboxrd@z Thu Jan  1 00:00:00 1970
From: Kamezawa Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Subject: Re: [PATCH v2 01/28] super: fix calculation of shrinkable objects
	for small numbers
Date: Mon, 01 Apr 2013 16:16:59 +0900
Message-ID: <5159346B.1000000@jp.fujitsu.com>
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Cc: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>, hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
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	Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
	linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
To: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
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(2013/03/29 18:13), Glauber Costa wrote:
> The sysctl knob sysctl_vfs_cache_pressure is used to determine which
> percentage of the shrinkable objects in our cache we should actively try
> to shrink.
> 
> It works great in situations in which we have many objects (at least
> more than 100), because the aproximation errors will be negligible. But
> if this is not the case, specially when total_objects < 100, we may end
> up concluding that we have no objects at all (total / 100 = 0,  if total
> < 100).
> 
> This is certainly not the biggest killer in the world, but may matter in
> very low kernel memory situations.
> 
> [ v2: fix it for all occurrences of sysctl_vfs_cache_pressure ]
> 
> Signed-off-by: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
> Reviewed-by: Carlos Maiolino <cmaiolino-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> CC: Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>
> CC: "Theodore Ts'o" <tytso-3s7WtUTddSA@public.gmane.org>
> CC: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>

I think reasonable.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>