From patchwork Fri Dec 1 12:02:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 13475709 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A03A1B4; Fri, 1 Dec 2023 04:02:20 -0800 (PST) Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4ShWlq02qgzShJS; Fri, 1 Dec 2023 19:57:59 +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 20:02:18 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Alexander Duyck , "Michael S. Tsirkin" , Jason Wang , Andrew Morton , Eric Dumazet , , , Subject: [PATCH RFC 2/6] page_frag: unify gfp bit for order 3 page allocation Date: Fri, 1 Dec 2023 20:02:03 +0800 Message-ID: <20231201120208.15080-3-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> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500005.china.huawei.com (7.185.36.74) X-CFilter-Loop: Reflected Currently there seems to be three page frag implementions which all try to allocate order 3 page, if that fails, it then fail back to allocate order 0 page, and each of them all allow order 3 page allocation to fail under certain condition by using specific gfp bits. The gfp bits for order 3 page allocation are different between different implementation, __GFP_NOMEMALLOC is or'd to forbid access to emergency reserves memory for __page_frag_cache_refill(), but it is not or'd in other implementions, __GFP_DIRECT_RECLAIM is xor'd to avoid direct reclaim in skb_page_frag_refill(), but it is not xor'd in __page_frag_cache_refill(). This patch unifies the gfp bits used between different implementions by or'ing __GFP_NOMEMALLOC and xor'ing __GFP_DIRECT_RECLAIM for order 3 page allocation to avoid possible pressure for mm. Signed-off-by: Yunsheng Lin CC: Alexander Duyck --- drivers/vhost/net.c | 2 +- mm/page_alloc.c | 4 ++-- net/core/sock.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index f2ed7167c848..e574e21cc0ca 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -670,7 +670,7 @@ static bool vhost_net_page_frag_refill(struct vhost_net *net, unsigned int sz, /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | - __GFP_NORETRY, + __GFP_NORETRY | __GFP_NOMEMALLOC, SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9a16305cf985..1f0b36dd81b5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4693,8 +4693,8 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, gfp_t gfp = gfp_mask; #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | - __GFP_NOMEMALLOC; + gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | + __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC; page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, PAGE_FRAG_CACHE_MAX_ORDER); nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; diff --git a/net/core/sock.c b/net/core/sock.c index fef349dd72fa..4efa9cae4b0d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2904,7 +2904,7 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp) /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | - __GFP_NORETRY, + __GFP_NORETRY | __GFP_NOMEMALLOC, SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;