From patchwork Thu May 4 10:09:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "zhaoyang.huang" X-Patchwork-Id: 13230991 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DF3AC77B7C for ; Thu, 4 May 2023 10:11:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2F4946B0075; Thu, 4 May 2023 06:11:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 27D8B6B0078; Thu, 4 May 2023 06:11:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 147626B007B; Thu, 4 May 2023 06:11:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from SHSQR01.spreadtrum.com (unknown [222.66.158.135]) by kanga.kvack.org (Postfix) with ESMTP id 8CA586B0075 for ; Thu, 4 May 2023 06:11:48 -0400 (EDT) Received: from SHSend.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by SHSQR01.spreadtrum.com with ESMTP id 344AAIsq063681; Thu, 4 May 2023 18:10:18 +0800 (+08) (envelope-from zhaoyang.huang@unisoc.com) Received: from bj03382pcu.spreadtrum.com (10.0.74.65) by BJMBX01.spreadtrum.com (10.0.64.7) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Thu, 4 May 2023 18:10:11 +0800 From: "zhaoyang.huang" To: Andrew Morton , Roman Gushchin , Roman Gushchin , , , Zhaoyang Huang , Subject: [PATCHv2] mm: optimization on page allocation when CMA enabled Date: Thu, 4 May 2023 18:09:54 +0800 Message-ID: <1683194994-3070-1-git-send-email-zhaoyang.huang@unisoc.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [10.0.74.65] X-ClientProxiedBy: SHCAS01.spreadtrum.com (10.0.1.201) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 344AAIsq063681 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Zhaoyang Huang Let us look at the series of scenarios below with WMARK_LOW=25MB,WMARK_MIN=5MB (managed pages 1.9GB). We can know that current 'fixed 1/2 ratio' start to use CMA since C which actually has caused U&R lower than WMARK_LOW (this should be deemed as against current memory policy, that is, U&R should either stay around WATERMARK_LOW when no allocation or do reclaim via enter slowpath) free_cma/free_pages(MB) A(12/30) B(12/25) C(12/20) fixed 1/2 ratio N N Y this commit Y Y Y Suggested-by: Roman Gushchin Signed-off-by: Zhaoyang Huang --- v2: do proportion check when zone_watermark_ok, update commit message --- --- mm/page_alloc.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0745aed..d0baeab 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3071,6 +3071,34 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, } +#ifdef CONFIG_CMA +static bool __if_use_cma_first(struct zone *zone, unsigned int order, unsigned int alloc_flags) +{ + unsigned long cma_proportion = 0; + unsigned long cma_free_proportion = 0; + unsigned long watermark = 0; + long count = 0; + bool cma_first = false; + + watermark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK); + /*check if GFP_MOVABLE pass previous watermark check via the help of CMA*/ + if (!zone_watermark_ok(zone, order, watermark, 0, alloc_flags & (~ALLOC_CMA))) + /* WMARK_LOW failed lead to using cma first, this helps U&R stay + * around low when being drained by GFP_MOVABLE + */ + cma_first = true; + else { + /*check proportion when zone_watermark_ok*/ + count = atomic_long_read(&zone->managed_pages); + cma_proportion = zone->cma_pages * 100 / count; + cma_free_proportion = zone_page_state(zone, NR_FREE_CMA_PAGES) * 100 + / zone_page_state(zone, NR_FREE_PAGES); + cma_first = (cma_free_proportion >= cma_proportion * 2 + || cma_free_proportion >= 50); + } + return cma_first; +} +#endif /* * Do the hard work of removing an element from the buddy allocator. * Call me with the zone->lock already held. @@ -3087,10 +3115,10 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, * allocating from CMA when over half of the zone's free memory * is in the CMA area. */ - if (alloc_flags & ALLOC_CMA && - zone_page_state(zone, NR_FREE_CMA_PAGES) > - zone_page_state(zone, NR_FREE_PAGES) / 2) { - page = __rmqueue_cma_fallback(zone, order); + if (migratetype == MIGRATE_MOVABLE) { + bool cma_first = __if_use_cma_first(zone, order, alloc_flags); + + page = cma_first ? __rmqueue_cma_fallback(zone, order) : NULL; if (page) return page; }