Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752423AbaLYKIx (ORCPT ); Thu, 25 Dec 2014 05:08:53 -0500 Received: from mx1.mxmail.xiaomi.com ([58.68.235.87]:19591 "EHLO mx1.mxmail.xiaomi.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751968AbaLYKIM (ORCPT ); Thu, 25 Dec 2014 05:08:12 -0500 From: Hui Zhu To: , , , , , , , , , , , , , , , , CC: , Hui Zhu Subject: [PATCH 3/3] CMA: Add cma_alloc_counter to make cma_alloc work better if it meet busy range Date: Thu, 25 Dec 2014 17:43:28 +0800 Message-ID: <1419500608-11656-4-git-send-email-zhuhui@xiaomi.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1419500608-11656-1-git-send-email-zhuhui@xiaomi.com> References: <1419500608-11656-1-git-send-email-zhuhui@xiaomi.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.27.14.101] X-ClientProxiedBy: CNCAS3.mioffice.cn (10.237.8.133) To cnbox4.mioffice.cn (10.237.8.144) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In [1], Joonsoo said that cma_alloc_counter is useless because pageblock is isolated. But if alloc_contig_range meet a busy range, it will undo_isolate_page_range before goto try next range. At this time, __rmqueue_cma can begin allocd CMA memory from the range. So I add cma_alloc_counter let __rmqueue doesn't call __rmqueue_cma when cma_alloc works. [1] https://lkml.org/lkml/2014/10/24/26 Signed-off-by: Hui Zhu --- include/linux/cma.h | 2 ++ mm/cma.c | 6 ++++++ mm/page_alloc.c | 8 +++++++- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/cma.h b/include/linux/cma.h index 9384ba6..155158f 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -26,6 +26,8 @@ extern int __init cma_declare_contiguous(phys_addr_t base, extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, int order_per_bit, struct cma **res_cma); + +extern atomic_t cma_alloc_counter; extern struct page *cma_alloc(struct cma *cma, int count, unsigned int align); extern bool cma_release(struct cma *cma, struct page *pages, int count); #endif diff --git a/mm/cma.c b/mm/cma.c index 6707b5d..b63f6be 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -348,6 +348,8 @@ err: return ret; } +atomic_t cma_alloc_counter = ATOMIC_INIT(0); + /** * cma_alloc() - allocate pages from contiguous area * @cma: Contiguous memory region for which the allocation is performed. @@ -378,6 +380,8 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align) bitmap_maxno = cma_bitmap_maxno(cma); bitmap_count = cma_bitmap_pages_to_bits(cma, count); + atomic_inc(&cma_alloc_counter); + for (;;) { mutex_lock(&cma->lock); bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap, @@ -415,6 +419,8 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align) start = bitmap_no + mask + 1; } + atomic_dec(&cma_alloc_counter); + pr_debug("%s(): returned %p\n", __func__, page); return page; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a5bbc38..0622c4c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -66,6 +66,10 @@ #include #include "internal.h" +#ifdef CONFIG_CMA +#include +#endif + /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ static DEFINE_MUTEX(pcp_batch_high_lock); #define MIN_PERCPU_PAGELIST_FRACTION (8) @@ -1330,7 +1334,9 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order, { struct page *page = NULL; - if (IS_ENABLED(CONFIG_CMA) && zone->managed_cma_pages) { + if (IS_ENABLED(CONFIG_CMA) + && zone->managed_cma_pages + && atomic_read(&cma_alloc_counter) == 0) { if (migratetype == MIGRATE_MOVABLE && zone->nr_try_movable <= 0) page = __rmqueue_cma(zone, order); -- 1.9.1 -- 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/