From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f170.google.com (mail-ig0-f170.google.com [209.85.213.170]) by kanga.kvack.org (Postfix) with ESMTP id D962D6B0069 for ; Thu, 16 Oct 2014 01:13:58 -0400 (EDT) Received: by mail-ig0-f170.google.com with SMTP id hn15so457119igb.3 for ; Wed, 15 Oct 2014 22:13:58 -0700 (PDT) Received: from mail-ig0-x229.google.com (mail-ig0-x229.google.com [2607:f8b0:4001:c05::229]) by mx.google.com with ESMTPS id f20si38991772icj.76.2014.10.15.22.13.58 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 15 Oct 2014 22:13:58 -0700 (PDT) Received: by mail-ig0-f169.google.com with SMTP id uq10so454717igb.4 for ; Wed, 15 Oct 2014 22:13:58 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1413430551-22392-1-git-send-email-zhuhui@xiaomi.com> References: <1413430551-22392-1-git-send-email-zhuhui@xiaomi.com> Date: Thu, 16 Oct 2014 13:13:57 +0800 Message-ID: Subject: Re: [PATCH 0/4] (CMA_AGGRESSIVE) Make CMA memory be more aggressive about allocation From: Weijie Yang Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Hui Zhu Cc: rjw@rjwysocki.net, len.brown@intel.com, pavel@ucw.cz, m.szyprowski@samsung.com, akpm@linux-foundation.org, mina86@mina86.com, aneesh.kumar@linux.vnet.ibm.com, iamjoonsoo.kim@lge.com, hannes@cmpxchg.org, riel@redhat.com, mgorman@suse.de, minchan@kernel.org, nasa4836@gmail.com, ddstreet@ieee.org, hughd@google.com, mingo@kernel.org, rientjes@google.com, peterz@infradead.org, keescook@chromium.org, atomlin@redhat.com, raistlin@linux.it, axboe@fb.com, paulmck@linux.vnet.ibm.com, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, k.khlebnikov@samsung.com, msalter@redhat.com, deller@gmx.de, tangchen@cn.fujitsu.com, ben@decadent.org.uk, akinobu.mita@gmail.com, lauraa@codeaurora.org, vbabka@suse.cz, sasha.levin@oracle.com, vdavydov@parallels.com, suleiman@google.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-mm@kvack.org On Thu, Oct 16, 2014 at 11:35 AM, Hui Zhu wrote: > In fallbacks of page_alloc.c, MIGRATE_CMA is the fallback of > MIGRATE_MOVABLE. > MIGRATE_MOVABLE will use MIGRATE_CMA when it doesn't have a page in > order that Linux kernel want. > > If a system that has a lot of user space program is running, for > instance, an Android board, most of memory is in MIGRATE_MOVABLE and > allocated. Before function __rmqueue_fallback get memory from > MIGRATE_CMA, the oom_killer will kill a task to release memory when > kernel want get MIGRATE_UNMOVABLE memory because fallbacks of > MIGRATE_UNMOVABLE are MIGRATE_RECLAIMABLE and MIGRATE_MOVABLE. > This status is odd. The MIGRATE_CMA has a lot free memory but Linux > kernel kill some tasks to release memory. I'm not very clear to this description, what issue do you try to solve? Make MIGRATE_CMA be the fallback of desired MIGRATE_UNMOVABLE? > This patch series adds a new function CMA_AGGRESSIVE to make CMA memory > be more aggressive about allocation. > If function CMA_AGGRESSIVE is available, when Linux kernel call function > __rmqueue try to get pages from MIGRATE_MOVABLE and conditions allow, > MIGRATE_CMA will be allocated as MIGRATE_MOVABLE first. If MIGRATE_CMA > doesn't have enough pages for allocation, go back to allocate memory from > MIGRATE_MOVABLE. I don't think so. That will cause MIGRATE_CMA depleted prematurely, and when a user(such as camera) wants CMA memory, he will not get the wanted memory. > Then the memory of MIGRATE_MOVABLE can be kept for MIGRATE_UNMOVABLE and > MIGRATE_RECLAIMABLE which doesn't have fallback MIGRATE_CMA. I don't think this is the root cause of oom. But I am interested in the CMA shrinker idea, I will follow this mail. Thanks for your work, add some test data will be better. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- 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