Re: [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien_cache().

All of lore.kernel.org
 help / color / mirror / Atom feed

From: Eric Dumazet <eric.dumazet@gmail.com>
To: Haicheng Li <haicheng.li@linux.intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>,
	linux-mm@kvack.org, Pekka Enberg <penberg@cs.helsinki.fi>,
	Matt Mackall <mpm@selenic.com>,
	andi@firstfloor.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien_cache().
Date: Wed, 23 Dec 2009 11:10:04 +0100	[thread overview]
Message-ID: <4B31EC7C.7000302@gmail.com> (raw)
In-Reply-To: <4B31BE44.1070308@linux.intel.com>

Le 23/12/2009 07:52, Haicheng Li a écrit :
> Christoph & Matt,
> 
> Thanks for the review. Node ids beyond nr_node_ids could be used in the
> case of
> memory hotadding.
> 
> Let me explain here:
> Firstly, original nr_node_ids = 1 + nid of highest POSSIBLE node.
> 
> Secondly, consider hotplug-adding the memories that are on a new_added
> node:
> 1. when acpi event is triggered:
> acpi_memory_device_add() -> acpi_memory_enable_device() -> add_memory()
> -> node_set_online()
> 
> The node_state[N_ONLINE] is updated with this new node added.
> And the id of this new node is beyond nr_node_ids.
> 

Then, this is a violation of the first statement :

nr_node_ids = 1 + nid of highest POSSIBLE node.

If your system allows hotplugging of new nodes, then POSSIBLE nodes should include them
at boot time.

Same thing for cpus and nr_cpus_ids. If a cpu is added, then its id MUST be < nr_cpus_ids

WARNING: multiple messages have this Message-ID (diff)

From: Eric Dumazet <eric.dumazet@gmail.com>
To: Haicheng Li <haicheng.li@linux.intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>,
	linux-mm@kvack.org, Pekka Enberg <penberg@cs.helsinki.fi>,
	Matt Mackall <mpm@selenic.com>,
	andi@firstfloor.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien_cache().
Date: Wed, 23 Dec 2009 11:10:04 +0100	[thread overview]
Message-ID: <4B31EC7C.7000302@gmail.com> (raw)
In-Reply-To: <4B31BE44.1070308@linux.intel.com>

Le 23/12/2009 07:52, Haicheng Li a ecrit :
> Christoph & Matt,
> 
> Thanks for the review. Node ids beyond nr_node_ids could be used in the
> case of
> memory hotadding.
> 
> Let me explain here:
> Firstly, original nr_node_ids = 1 + nid of highest POSSIBLE node.
> 
> Secondly, consider hotplug-adding the memories that are on a new_added
> node:
> 1. when acpi event is triggered:
> acpi_memory_device_add() -> acpi_memory_enable_device() -> add_memory()
> -> node_set_online()
> 
> The node_state[N_ONLINE] is updated with this new node added.
> And the id of this new node is beyond nr_node_ids.
> 

Then, this is a violation of the first statement :

nr_node_ids = 1 + nid of highest POSSIBLE node.

If your system allows hotplugging of new nodes, then POSSIBLE nodes should include them
at boot time.

Same thing for cpus and nr_cpus_ids. If a cpu is added, then its id MUST be < nr_cpus_ids

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

next prev parent reply	other threads:[~2009-12-23 10:10 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-22 12:38 [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien_cache() Haicheng Li
2009-12-22 12:38 ` Haicheng Li
2009-12-22 12:40 ` Andi Kleen
2009-12-22 12:40   ` Andi Kleen
2009-12-22 15:47 ` Christoph Lameter
2009-12-22 15:47   ` Christoph Lameter
2009-12-23  6:52   ` Haicheng Li
2009-12-23  6:52     ` Haicheng Li
2009-12-23 10:10     ` Eric Dumazet [this message]
2009-12-23 10:10       ` Eric Dumazet
2009-12-23 10:23       ` Andi Kleen
2009-12-23 10:23         ` Andi Kleen
2009-12-23 11:23         ` Haicheng Li
2009-12-23 11:23           ` Haicheng Li
2010-01-04 17:26           ` Christoph Lameter
2010-01-04 17:26             ` Christoph Lameter
2009-12-22 22:38 ` Matt Mackall
2009-12-22 22:38   ` Matt Mackall
2009-12-23  9:58   ` [PATCH v2] " Haicheng Li
2009-12-23  9:58     ` Haicheng Li
2010-01-04 17:27     ` Christoph Lameter
2010-01-04 17:27       ` Christoph Lameter

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4B31EC7C.7000302@gmail.com \
    --to=eric.dumazet@gmail.com \
    --cc=andi@firstfloor.org \
    --cc=cl@linux-foundation.org \
    --cc=haicheng.li@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mpm@selenic.com \
    --cc=penberg@cs.helsinki.fi \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Be sure your reply has a Subject: header at the top and a blank line before the message body.

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.