Home » Mailing list archives » linux-kernel » 2007 » September » 20

[PATCH 0/1] x86: Reduce Memory Usage for large CPU count systems

!MAILaRCHIVE_VOTE_RePLACE
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
[view in full thread]
From: <travis@...>
To: Andi Kleen <ak@...>, Andrew Morton <akpm@...>
Cc: Christoph Lameter <clameter@...>, Jack Steiner <steiner@...>, <linux-mm@...>, <linux-kernel@...>
Subject: [PATCH 0/1] x86: Reduce Memory Usage for large CPU count systems
Date: Thursday, September 20, 2007 - 4:49 pm

Analyzing various data structures when NR_CPU count is raised
to 4096 shows the following arrays over 128k.  If the maximum
number of cpus are not installed (about 99.99% of the time),
then a large percentage of this memory is wasted.
--
	151289856  CALNDATA  irq_desc
	135530496  RMDATATA  irq_cfg
	  3145728  CALNDATA  cpu_data
	  2101248  BSS       irq_lists
	  2097152  RMDATATA  cpu_sibling_map
	  2097152  RMDATATA  cpu_core_map
	  1575936  BSS       irq_2_pin
	  1050624  BSS       irq_timer_state
	   614400  INITDATA  early_node_map
	   525376  PERCPU    per_cpu__kstat
	   524608  DATA      unix_proto
	   524608  DATA      udpv6_prot
	   524608  DATA      udplitev6_prot
	   524608  DATA      udplite_prot
	   524608  DATA      udp_prot
	   524608  DATA      tcpv6_prot
	   524608  DATA      tcp_prot
	   524608  DATA      rawv6_prot
	   524608  DATA      raw_prot
	   524608  DATA      packet_proto
	   524608  DATA      netlink_proto
	   524288  BSS       cpu_devices
	   524288  BSS       boot_pageset
	   524288  CALNDATA  boot_cpu_pda
	   262144  RMDATATA  node_to_cpumask
	   262144  BSS       __log_buf
	   131072  BSS       entries

cpu_sibling_map and cpu_core_map have been taken care of in
a prior patch.  This patch deals with the cpu_data array of
cpuinfo_x86 structs.  The model that was used in sparc64
architecture was adopted for x86.

Obviously, the IRQ arrays are of greater importance for
size reduction.  Any suggestions, or threads I should read
are gratefully accecpted... ;-)

-- 
-
Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
Messages in current thread:
[PATCH 0/1] x86: Reduce Memory Usage for large CPU count sys..., , (Thu Sep 20, 4:49 pm)