From patchwork Tue Jul 9 13:27:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 13727993 X-Patchwork-Delegate: kuba@kernel.org Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C8C2176AC0; Tue, 9 Jul 2024 13:31:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720531879; cv=none; b=nXaf/gVThRXs4M664WWwjZOSetq9C+IYcClvChux/C2EICVtVY36pHYL2o8ZF+mrdGtRKI3i9OHzc0iZx32F48nFwVt/H4wXQOECaYirBcQe9Q5cOhZ2m+LSKDYuLai37h7lAdazLr/bPN3AyNq72dJuYNlgCyVP8StLZIrx4Qo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720531879; c=relaxed/simple; bh=B3+hPNPGvnyr5YEHeRboytbpmreuTuxrsVJRPFkUMjc=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=l+pTOvxv55eyUfnUeeznSpziHHtxeOM7+XabqXCyTj0hUaNAkXA4eKcJMwUHa9NUh6feUyb4xi5LcaY9UHahP1NPCAV63RM/3CoVQnAix9XJOGAEONSjSJTJQzKhDYM18t2q3ohyPBuddV49w/EFSAuHKCjsq6CmbSfL0e/f8Gc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4WJMLw68S9zcpK6; Tue, 9 Jul 2024 21:30:48 +0800 (CST) Received: from dggpemf200006.china.huawei.com (unknown [7.185.36.61]) by mail.maildlp.com (Postfix) with ESMTPS id 0B10C140258; Tue, 9 Jul 2024 21:31:15 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpemf200006.china.huawei.com (7.185.36.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 9 Jul 2024 21:31:14 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Alexander Duyck , Andrew Morton , Subject: [PATCH net-next v10 08/15] mm: page_frag: some minor refactoring before adding new API Date: Tue, 9 Jul 2024 21:27:33 +0800 Message-ID: <20240709132741.47751-9-linyunsheng@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20240709132741.47751-1-linyunsheng@huawei.com> References: <20240709132741.47751-1-linyunsheng@huawei.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemf200006.china.huawei.com (7.185.36.61) X-Patchwork-Delegate: kuba@kernel.org Refactor common codes from __page_frag_alloc_va_align() to __page_frag_cache_refill(), so that the new API can make use of them. CC: Alexander Duyck Signed-off-by: Yunsheng Lin --- include/linux/page_frag_cache.h | 2 +- mm/page_frag_cache.c | 96 +++++++++++++++++---------------- 2 files changed, 50 insertions(+), 48 deletions(-) diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h index 87c3eb728f95..71e08db1eb2f 100644 --- a/include/linux/page_frag_cache.h +++ b/include/linux/page_frag_cache.h @@ -68,7 +68,7 @@ struct page_frag_cache { static inline void page_frag_cache_init(struct page_frag_cache *nc) { - nc->encoded_va = 0; + memset(nc, 0, sizeof(*nc)); } static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc) diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c index 02e4ec92f948..73164d2482f8 100644 --- a/mm/page_frag_cache.c +++ b/mm/page_frag_cache.c @@ -19,6 +19,28 @@ #include #include "internal.h" +static struct page *__page_frag_cache_recharge(struct page_frag_cache *nc) +{ + unsigned long encoded_va = nc->encoded_va; + struct page *page; + + page = virt_to_page((void *)encoded_va); + if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) + return NULL; + + if (unlikely(encoded_page_pfmemalloc(encoded_va))) { + VM_BUG_ON(compound_order(page) != + encoded_page_order(encoded_va)); + free_unref_page(page, encoded_page_order(encoded_va)); + return NULL; + } + + /* OK, page count is 0, we can safely set it */ + set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); + + return page; +} + static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, gfp_t gfp_mask) { @@ -26,6 +48,14 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, struct page *page = NULL; gfp_t gfp = gfp_mask; + if (likely(nc->encoded_va)) { + page = __page_frag_cache_recharge(nc); + if (page) { + order = encoded_page_order(nc->encoded_va); + goto out; + } + } + #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC; @@ -35,7 +65,7 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, if (unlikely(!page)) { page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); if (unlikely(!page)) { - nc->encoded_va = 0; + memset(nc, 0, sizeof(*nc)); return NULL; } @@ -45,6 +75,16 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, nc->encoded_va = encode_aligned_va(page_address(page), order, page_is_pfmemalloc(page)); + /* Even if we own the page, we do not use atomic_set(). + * This would break get_page_unless_zero() users. + */ + page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); + +out: + /* reset page count bias and remaining to start of new frag */ + nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + nc->remaining = PAGE_SIZE << order; + return page; } @@ -55,7 +95,7 @@ void page_frag_cache_drain(struct page_frag_cache *nc) __page_frag_cache_drain(virt_to_head_page((void *)nc->encoded_va), nc->pagecnt_bias); - nc->encoded_va = 0; + memset(nc, 0, sizeof(*nc)); } EXPORT_SYMBOL(page_frag_cache_drain); @@ -72,53 +112,15 @@ void *__page_frag_alloc_va_align(struct page_frag_cache *nc, unsigned int fragsz, gfp_t gfp_mask, unsigned int align_mask) { - unsigned long encoded_va = nc->encoded_va; - int aligned_remaining, remaining; - unsigned int size; - struct page *page; - - if (unlikely(!encoded_va)) { -refill: - page = __page_frag_cache_refill(nc, gfp_mask); - if (!page) - return NULL; - - encoded_va = nc->encoded_va; - size = page_frag_cache_page_size(encoded_va); + unsigned int size = page_frag_cache_page_size(nc->encoded_va); + int aligned_remaining = nc->remaining & align_mask; + int remaining = aligned_remaining - fragsz; - /* Even if we own the page, we do not use atomic_set(). - * This would break get_page_unless_zero() users. - */ - page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); - - /* reset page count bias and remaining to start of new frag */ - nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - nc->remaining = size; - } - - size = page_frag_cache_page_size(encoded_va); - - aligned_remaining = nc->remaining & align_mask; - remaining = aligned_remaining - fragsz; if (unlikely(remaining < 0)) { - page = virt_to_page((void *)encoded_va); - - if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) - goto refill; - - if (unlikely(encoded_page_pfmemalloc(encoded_va))) { - VM_BUG_ON(compound_order(page) != - encoded_page_order(encoded_va)); - free_unref_page(page, encoded_page_order(encoded_va)); - goto refill; - } - - /* OK, page count is 0, we can safely set it */ - set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); + if (!__page_frag_cache_refill(nc, gfp_mask)) + return NULL; - /* reset page count bias and remaining to start of new frag */ - nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - nc->remaining = size; + size = page_frag_cache_page_size(nc->encoded_va); aligned_remaining = size; remaining = aligned_remaining - fragsz; @@ -139,7 +141,7 @@ void *__page_frag_alloc_va_align(struct page_frag_cache *nc, nc->pagecnt_bias--; nc->remaining = remaining; - return encoded_page_address(encoded_va) + (size - aligned_remaining); + return encoded_page_address(nc->encoded_va) + (size - aligned_remaining); } EXPORT_SYMBOL(__page_frag_alloc_va_align);