From patchwork Mon Oct 28 11:58:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 13853393 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 7232D1DCB2C; Mon, 28 Oct 2024 12:05:38 +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=1730117142; cv=none; b=nLd1UQAZ0B/CbTKTp6VhXaBTuLQ3tY8Q6PX5XZjQCb92amIH27hngtCyY1lRjBqlV/w5UhYdE7d62r5apEC8xKHaUUv8vE4Tvy3S86CSEwFD5oJRV17MZnFfUL22Fy4NzP+jpqOgh/tlpnX6uf+XPBDhEEw9RW0ylEIhx/ZEtO8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730117142; c=relaxed/simple; bh=u7Y8vcACw0nN7XvzUTUQjb+zsdFCruoZHnJv/2+6AWE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=q/Z8Zy2hE7bXNjBEdjEOmc+lqrVBmfUI0FNBdc0l9dPAs6aKd62OpSE9hiUtwj/fFwky8cjmfPz3uWvaO9l765gPf9/0B+mGeS95q7vJlr+DtIf3I4F4SaOO0ZYhXYOwozjGMymoFcKGESp6V8/w5C0mgWFE3hsy0S3x5+CA/68= 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 [172.19.88.194]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4XcX8d5bshzpWPn; Mon, 28 Oct 2024 20:03:13 +0800 (CST) Received: from dggpemf200006.china.huawei.com (unknown [7.185.36.61]) by mail.maildlp.com (Postfix) with ESMTPS id B9F5A1402CB; Mon, 28 Oct 2024 20:05:09 +0800 (CST) Received: from localhost.localdomain (10.90.30.45) 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; Mon, 28 Oct 2024 20:05:09 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Alexander Duyck , Andrew Morton , Linux-MM Subject: [PATCH RFC 01/10] mm: page_frag: some minor refactoring before adding new API Date: Mon, 28 Oct 2024 19:58:41 +0800 Message-ID: <20241028115850.3409893-2-linyunsheng@huawei.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20241028115850.3409893-1-linyunsheng@huawei.com> References: <20241028115850.3409893-1-linyunsheng@huawei.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemf200006.china.huawei.com (7.185.36.61) X-Patchwork-State: RFC Refactor common codes from __page_frag_alloc_va_align() to __page_frag_cache_prepare() and __page_frag_cache_commit(), so that the new API can make use of them. CC: Alexander Duyck CC: Andrew Morton CC: Linux-MM Signed-off-by: Yunsheng Lin --- include/linux/page_frag_cache.h | 34 ++++++++++++++++++++++++++-- mm/page_frag_cache.c | 40 ++++++++++++++++++++++++++------- 2 files changed, 64 insertions(+), 10 deletions(-) diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h index 41a91df82631..5ae97f93a0a1 100644 --- a/include/linux/page_frag_cache.h +++ b/include/linux/page_frag_cache.h @@ -5,6 +5,7 @@ #include #include +#include #include #include @@ -39,8 +40,37 @@ static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc) void page_frag_cache_drain(struct page_frag_cache *nc); void __page_frag_cache_drain(struct page *page, unsigned int count); -void *__page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, - gfp_t gfp_mask, unsigned int align_mask); +void *__page_frag_cache_prepare(struct page_frag_cache *nc, unsigned int fragsz, + struct page_frag *pfrag, gfp_t gfp_mask, + unsigned int align_mask); +unsigned int __page_frag_cache_commit_noref(struct page_frag_cache *nc, + struct page_frag *pfrag, + unsigned int used_sz); + +static inline unsigned int __page_frag_cache_commit(struct page_frag_cache *nc, + struct page_frag *pfrag, + unsigned int used_sz) +{ + VM_BUG_ON(!nc->pagecnt_bias); + nc->pagecnt_bias--; + + return __page_frag_cache_commit_noref(nc, pfrag, used_sz); +} + +static inline void *__page_frag_alloc_align(struct page_frag_cache *nc, + unsigned int fragsz, gfp_t gfp_mask, + unsigned int align_mask) +{ + struct page_frag page_frag; + void *va; + + va = __page_frag_cache_prepare(nc, fragsz, &page_frag, gfp_mask, + align_mask); + if (likely(va)) + __page_frag_cache_commit(nc, &page_frag, fragsz); + + return va; +} static inline void *page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, gfp_t gfp_mask, diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c index 3f7a203d35c6..f55d34cf7d43 100644 --- a/mm/page_frag_cache.c +++ b/mm/page_frag_cache.c @@ -90,9 +90,31 @@ void __page_frag_cache_drain(struct page *page, unsigned int count) } EXPORT_SYMBOL(__page_frag_cache_drain); -void *__page_frag_alloc_align(struct page_frag_cache *nc, - unsigned int fragsz, gfp_t gfp_mask, - unsigned int align_mask) +unsigned int __page_frag_cache_commit_noref(struct page_frag_cache *nc, + struct page_frag *pfrag, + unsigned int used_sz) +{ + unsigned int orig_offset; + + VM_BUG_ON(used_sz > pfrag->size); + VM_BUG_ON(pfrag->page != encoded_page_decode_page(nc->encoded_page)); + VM_BUG_ON(pfrag->offset + pfrag->size > + (PAGE_SIZE << encoded_page_decode_order(nc->encoded_page))); + + /* pfrag->offset might be bigger than the nc->offset due to alignment */ + VM_BUG_ON(nc->offset > pfrag->offset); + + orig_offset = nc->offset; + nc->offset = pfrag->offset + used_sz; + + /* Return true size back to caller considering the offset alignment */ + return nc->offset - orig_offset; +} +EXPORT_SYMBOL(__page_frag_cache_commit_noref); + +void *__page_frag_cache_prepare(struct page_frag_cache *nc, unsigned int fragsz, + struct page_frag *pfrag, gfp_t gfp_mask, + unsigned int align_mask) { unsigned long encoded_page = nc->encoded_page; unsigned int size, offset; @@ -114,6 +136,8 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc, /* reset page count bias and offset to start of new frag */ nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; nc->offset = 0; + } else { + page = encoded_page_decode_page(encoded_page); } size = PAGE_SIZE << encoded_page_decode_order(encoded_page); @@ -132,8 +156,6 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc, return NULL; } - page = encoded_page_decode_page(encoded_page); - if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) goto refill; @@ -148,15 +170,17 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc, /* reset page count bias and offset to start of new frag */ nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + nc->offset = 0; offset = 0; } - nc->pagecnt_bias--; - nc->offset = offset + fragsz; + pfrag->page = page; + pfrag->offset = offset; + pfrag->size = size - offset; return encoded_page_decode_virt(encoded_page) + offset; } -EXPORT_SYMBOL(__page_frag_alloc_align); +EXPORT_SYMBOL(__page_frag_cache_prepare); /* * Frees a page fragment allocated out of either a compound or order 0 page.