From: Christoph Lameter <clameter@sgi.com>
To: "Martin J. Bligh" <mbligh@google.com>
Cc: akpm@osdl.org, linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH 00/14] Zoned VM counters V5
Date: Wed, 21 Jun 2006 10:06:15 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.64.0606211001370.19596@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <44997596.7050903@google.com>
On Wed, 21 Jun 2006, Martin J. Bligh wrote:
> Having the per-cpu counters with a global overflow seems like a really
> nice way to do counters to me - is it worth doing this as a more
> generalized counter type so that others could use it?
Yes later patches also use the counters for other things. Please check out
the patch that uses these for numa counters etc.
> OTOH, I'm unsure why we're only using 8 bits in struct zone, which isn't
> size critical. Is it just so you can pack vast numbers of different stats into
> a single cacheline?
I would like to add some stats in the future. 8 bits is sufficient if the
threshold is less than 64 (currently its 32). If we ever get higher then
we can simply go to a bigger base size.
However, the space used by that array is
<nr-of-counters>*<nr_of_processors>*<nr_of_zones>
There are systems that have around 1k nodes and 4k processors. Lets say
we have 16 counters then we get to
1k*4k*16 = 64Mbyte just for the counters.
This doubles for a short and quadruples for an int.
Also smaller counters help keep the pcp structure in one cacheline and
reduces the cache footprint.
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next prev parent reply other threads:[~2006-06-21 17:06 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-21 15:44 Christoph Lameter
2006-06-21 15:44 ` [PATCH 01/14] Create vmstat.c/.h from page_alloc.c/.h Christoph Lameter
2006-06-21 15:44 ` [PATCH 02/14] Basic ZVC (zoned vm counter) implementation, zoned vm counters: per zone counter functionality Christoph Lameter, Christoph Lameter
[not found] ` <20060622041034.84b3c997.akpm@osdl.org>
2006-06-22 14:54 ` [PATCH 02/14] Basic ZVC (zoned vm counter) implementation Christoph Lameter
2006-06-21 15:44 ` [PATCH 03/14] Convert nr_mapped to per zone counter, zoned vm counters: conversion of nr_mapped to per zone counter Christoph Lameter, Christoph Lameter
2006-06-21 15:44 ` [PATCH 04/14] Conversion of nr_pagecache to per zone counter, zoned vm counters: conversion of nr_pagecache " Christoph Lameter, Christoph Lameter
2006-06-21 15:44 ` [PATCH 05/14] Remove NR_FILE_MAPPED from scan control structure, zoned VM stats: Remove nr_mapped from scan control Christoph Lameter, Christoph Lameter
2006-06-21 15:44 ` [PATCH 06/14] Split NR_ANON_PAGES off from NR_FILE_MAPPED, zoned VM stats: Add NR_ANON_PAGES Christoph Lameter, Christoph Lameter
[not found] ` <44996F34.1010805@google.com>
2006-06-21 17:01 ` [PATCH 06/14] Split NR_ANON_PAGES off from NR_FILE_MAPPED Christoph Lameter
2006-06-21 15:44 ` [PATCH 07/14] zone_reclaim: remove /proc/sys/vm/zone_reclaim_interval, zoned vm counters: use per zone counters to remove zone_reclaim_interval Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 08/14] Conversion of nr_slab to per zone counter, zoned vm counters: conversion of nr_slab to per zone counter Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 09/14] Conversion of nr_pagetables to per zone counter, zoned vm counters: conversion of nr_pagetable " Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 10/14] Conversion of nr_dirty to per zone counter, zoned vm counters: conversion of nr_dirty " Christoph Lameter, Christoph Lameter
[not found] ` <20060624050424.d2160354.akpm@osdl.org>
2006-06-24 18:14 ` [PATCH 10/14] Conversion " Christoph Lameter
2006-06-24 20:53 ` Christoph Lameter
2006-06-21 15:45 ` [PATCH 11/14] Conversion of nr_writeback to per zone counter, zoned vm counters: conversion of nr_writeback " Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 12/14] Conversion of nr_unstable to per zone counter, zoned vm counters: conversion of nr_unstable " Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 13/14] Conversion of nr_bounce to per zone counter, zoned vm counters: conversion of nr_bounce " Christoph Lameter, Christoph Lameter
2006-06-21 15:45 ` [PATCH 14/14] Remove useless struct wbs, zoned vm counters: remove useless writeback structure Christoph Lameter, Christoph Lameter
2006-06-21 16:36 ` [PATCH 00/14] Zoned VM counters V5 Martin J. Bligh
2006-06-21 17:06 ` Christoph Lameter [this message]
2006-06-21 17:10 ` Martin Bligh
2006-06-21 17:16 ` Christoph Lameter
2006-06-21 17:21 ` Martin Bligh
2006-06-21 17:29 ` Christoph Lameter
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