From patchwork Fri Dec 1 12:02:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 13475706 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 D8CBDC4167B for ; Fri, 1 Dec 2023 12:02:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 198888D0072; Fri, 1 Dec 2023 07:02:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1218E8D0001; Fri, 1 Dec 2023 07:02:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F29898D0072; Fri, 1 Dec 2023 07:02:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id E2D648D0001 for ; Fri, 1 Dec 2023 07:02:26 -0500 (EST) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id B98CD120212 for ; Fri, 1 Dec 2023 12:02:26 +0000 (UTC) X-FDA: 81518111892.16.E25BB7F Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf21.hostedemail.com (Postfix) with ESMTP id 1BE171C0013 for ; Fri, 1 Dec 2023 12:02:23 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf21.hostedemail.com: domain of linyunsheng@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linyunsheng@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1701432145; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sY6rt6ZDWSPLy+R4GC8GwC8YJzCuoyXBaVHV+cH68pA=; b=Ri8JkbNrxIq1fw1M0MaCvp2k4/nVzAhRZRcAR1kaLCYLheeb6sElUOJwXnoRJIT+nudxRC ZnAxbcmmmUHlvReY3U+vI5GgQgiPxDJp21ozGSp2E1kd3BjmBlbYTEGjKwk9wgij3FyZdv farAb6g4v8IyZeXn6p736hCC5jV/IKM= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf21.hostedemail.com: domain of linyunsheng@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linyunsheng@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1701432145; a=rsa-sha256; cv=none; b=ohzFPok+13Gjo08kN588mOW06h4GuA5qp8sMj/eLCxlndLG/LoXSOwdGZrSecnIhXo2PYV hX9/6198zoSyL2ySdzBIFNSsNfIm1CbIVP4zGQwKM6mEMXf6FUnL1FuS20bMlROLI1RLw2 jopoQSkyqjzfZhdB8OQw8H/JKMHw6w8= Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4ShWqx2WS9zWhx4; Fri, 1 Dec 2023 20:01:33 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpemm500005.china.huawei.com (7.185.36.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Fri, 1 Dec 2023 20:02:20 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Alexander Duyck , Andrew Morton , Subject: [PATCH RFC 3/6] mm/page_alloc: use initial zero offset for page_frag_alloc_align() Date: Fri, 1 Dec 2023 20:02:04 +0800 Message-ID: <20231201120208.15080-4-linyunsheng@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231201120208.15080-1-linyunsheng@huawei.com> References: <20231201120208.15080-1-linyunsheng@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500005.china.huawei.com (7.185.36.74) X-CFilter-Loop: Reflected X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 1BE171C0013 X-Stat-Signature: nu99i5ehc83ahcwe7nfs6p6od4ug5nfj X-HE-Tag: 1701432143-998551 X-HE-Meta: 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 S9JBJSAf 8DTR7R8+ugH4hHj5NDeDGkec3u0h4clp348QlS3joQDKiIIgUjOsZZVP+HoXJU5EN/nRbH63Dh7S7Tqu1+aOpHj3co4pqRrLbgRPWffstf7kYX4eSWPThiaCUUjhwYosvXitOiOYRljjPeRJjF26FPsnMQ76O8rQhR11/EF2vmEvYMwk6Ew9SKGHz0NabUvM73pLMrLq6zVGW0bMALrjx+Ky+2dfAa38ksi6n32CFcczj6AAg9Gh3kPlyIMQ6H5vaIYqjxyOs6y7qFYDD86EpEsGMWeI6Bq8idzL6 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: List-Subscribe: List-Unsubscribe: The next patch is above to use page_frag_alloc_align() to replace vhost_net_page_frag_refill(), the main difference between those two frag page implementations is whether we use a initial zero offset or not. It seems more nature to use a initial zero offset, as it may enable more correct cache prefetching and skb frag coalescing in the networking, so change it to use initial zero offset. Signed-off-by: Yunsheng Lin CC: Alexander Duyck --- mm/page_alloc.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1f0b36dd81b5..083e0c38fb62 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4720,7 +4720,7 @@ void *page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, gfp_t gfp_mask, unsigned int align) { - unsigned int size = PAGE_SIZE; + unsigned int size; struct page *page; int offset; @@ -4732,10 +4732,6 @@ void *page_frag_alloc_align(struct page_frag_cache *nc, if (!page) return NULL; -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - /* if size can vary use size else just use PAGE_SIZE */ - size = nc->size; -#endif /* Even if we own the page, we do not use atomic_set(). * This would break get_page_unless_zero() users. */ @@ -4744,11 +4740,18 @@ void *page_frag_alloc_align(struct page_frag_cache *nc, /* reset page count bias and offset to start of new frag */ nc->pfmemalloc = page_is_pfmemalloc(page); nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - nc->offset = size; + nc->offset = 0; } - offset = nc->offset - fragsz; - if (unlikely(offset < 0)) { +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + /* if size can vary use size else just use PAGE_SIZE */ + size = nc->size; +#else + size = PAGE_SIZE; +#endif + + offset = ALIGN(nc->offset, align); + if (unlikely(offset + fragsz > size)) { page = virt_to_page(nc->va); if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) @@ -4759,17 +4762,13 @@ void *page_frag_alloc_align(struct page_frag_cache *nc, goto refill; } -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - /* if size can vary use size else just use PAGE_SIZE */ - size = nc->size; -#endif /* OK, page count is 0, we can safely set it */ set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); /* reset page count bias and offset to start of new frag */ nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - offset = size - fragsz; - if (unlikely(offset < 0)) { + offset = 0; + if (unlikely(fragsz > size)) { /* * The caller is trying to allocate a fragment * with fragsz > PAGE_SIZE but the cache isn't big @@ -4784,8 +4783,7 @@ void *page_frag_alloc_align(struct page_frag_cache *nc, } nc->pagecnt_bias--; - offset &= -align; - nc->offset = offset; + nc->offset = offset + fragsz; return nc->va + offset; }