From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <478CD18B.9050705@bull.net> Date: Tue, 15 Jan 2008 16:30:19 +0100 From: Nadia Derbey MIME-Version: 1.0 Subject: Re: [RFC PATCH 0/4] [RESEND] Change default MSGMNI tunable to scale with lowmem References: <478CCEA3.5050404@bull.net> In-Reply-To: <478CCEA3.5050404@bull.net> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii; format=flowed Sender: owner-linux-mm@kvack.org Return-Path: To: containers@lists.osdl.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Resending with the right address for the containers mailing list. So sorry... Nadia Derbey wrote: > Hi, > > Yesterday, I posted to lkml a series of patches that make the ipc > tunable msgmni scale with lowmem (see thread > http://lkml.org/lkml/2008/1/14/196). > > Since these patches watch for memory hotplug notifications, I thought > that comments from linux-mm people would be interesting. > > Also, since these patches change the ipc_namespace structure, comments > from people subscribed at the containers mailing list would be welcome too. > > Notes: > 1) please, Cc me since I'm not subscribed to linux-mm. > 2) sorry for lkml subsribers who are receiving this mail for the 2nd > time, but I wanted all the comments to be shared. > > > Here is patch 0, the complete series can be found in the thread > mentioned above. > > ----------------- > > On large systems we'd like to allow a larger number of message queues. > In some cases up to 32K. However simply setting MSGMNI to a larger value > may cause problems for smaller systems. > > The first patch of this series introduces a default maximum number of > message queue ids that scales with the amount of lowmem. > > Since msgmni is per namespace and there is no amount of memory dedicated > to each namespace so far, the second patch of this series scales msgmni > to the number of ipc namespaces. > > In the last patch, a notifier block is added to the ipc namespace > structure to manage memory hotplug. The callback routine is activated > upon memory add/remove and it recomputes msgmni. One callback routine is > added to the memory notifier chain each time an ipc namespace is > allocated. It is removed when the coresponding ipc namespace is freed. > > I still have 1 issue that I'll try to solve next: > . use the notification mechanism to recompute all the msg_ctlmni each > time an ipc namespace is created / removed. > > > These patches should be applied to 2.6.24-rc7, in the following order: > > [PATCH 1/4]: ipc_scale_msgmni_with_lowmem.patch > [PATCH 2/4]: ipc_scale_msgmni_with_namespaces.patch > [PATCH 3/4]: ipc_slab_memory_callback_prio_to_const.patch > [PATCH 4/4]: ipc_recompute_msgmni_on_memory_hotplug.patch > > > Regards, > Nadia > -- 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: email@kvack.org