From nobody Fri Dec 19 06:31:11 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4C00A1F934 for ; Fri, 28 Jun 2024 03:06:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719544013; cv=none; b=ip50CXDHpsQdohYjjpih0qV2cQlm9xUkN34n9sKDNEO8pcXbLSZcc9wFvWgIxVEWRWkhmbtH1G0bu+5x6t+GCbJi1NtcA8DwkJ47UW+YMPA3mYBDWcV7NO5gIbgLuLBdygviIuurn9prFgG31ldPTGH+H3CppzPPexbx3/jYRJk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719544013; c=relaxed/simple; bh=Cr0rk228Nf4Ejmcf123tMGr+wVgBtKk7ChztlR6oqcc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UhGgOWJ/NnYRjFtQ9auYU0yUrQd2KuoykgqME+ROqw0ex03iTif0MHxTK/7rAclIlAzOBZxc7oEfW832dv5voSgdYdWL9itA7jVDOM8mxEvlWd52Ep0D+79odJV1Osova+7KlxxyD2OgnXhtjAeDJtEhlm6LMga0VciQjh03KxA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C87rd9lC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C87rd9lC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01F3FC4AF09; Fri, 28 Jun 2024 03:06:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719544012; bh=Cr0rk228Nf4Ejmcf123tMGr+wVgBtKk7ChztlR6oqcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C87rd9lCAIEm3gmgN1HsqdNpdHVQnk+7Q4Nv5dOer+u/gx8+vllp84o4qmsNwEaZg +Fe1YLW2saEdNkRrbeqC8q7l72FvR+c0OCa5xkz+05L0MavtAPM7hr/UDfktBh/QSb oJjlWdO597SbcB/MMgnDSkhzMxI2B6jMBPx9yG08XhP6Go5Ay+7NS4e/baBvqUc1sO eFslcQG/0/9QdUnqkjnahncWxOulT4eXMZVUN0hMXgwqy8SzeqVX0Aj7BXIoByXD3F WgfD365aGDEcOL1toHZ63a0fAY+j4Rit+f8tKukzw1F/O63OwIGXMV+jk/g1251juN woROqUiGIiSlQ== From: alexs@kernel.org To: Vitaly Wool , Miaohe Lin , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, minchan@kernel.org, willy@infradead.org, senozhatsky@chromium.org, david@redhat.com, 42.hyeyoo@gmail.com Cc: Alex Shi Subject: [PATCH 01/20] mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool Date: Fri, 28 Jun 2024 11:11:16 +0800 Message-ID: <20240628031138.429622-2-alexs@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240628031138.429622-1-alexs@kernel.org> References: <20240628031138.429622-1-alexs@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Alex Shi The 1st patch introduces new memory decriptor zpdesc and rename zspage.first_page to zspage.first_zpdesc, no functional change. Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi --- mm/zpdesc.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ mm/zsmalloc.c | 19 ++++++++--------- 2 files changed, 66 insertions(+), 9 deletions(-) create mode 100644 mm/zpdesc.h diff --git a/mm/zpdesc.h b/mm/zpdesc.h new file mode 100644 index 000000000000..a1ab5ebaa936 --- /dev/null +++ b/mm/zpdesc.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* zpdesc.h: zswap.zpool memory descriptor + * + * Written by Alex Shi + * Hyeonggon Yoo <42.hyeyoo@gmail.com> + */ +#ifndef __MM_ZPDESC_H__ +#define __MM_ZPDESC_H__ + +/* + * struct zpdesc - Memory descriptor for zpool memory, now is for zsmalloc + * @flags: Page flags, PG_private: identifies the first component page + * @lru: Indirected used by page migration + * @next: Next zpdesc in a zspage in zsmalloc zpool + * @handle: For huge zspage in zsmalloc zpool + * @zspage: Pointer to zspage in zsmalloc + * + * This struct overlays struct page for now. Do not modify without a good + * understanding of the issues. + */ +struct zpdesc { + unsigned long flags; + struct list_head lru; + unsigned long _zp_pad_1; + union { + /* Next zpdescs in a zspage in zsmalloc zpool */ + struct zpdesc *next; + /* For huge zspage in zsmalloc zpool */ + unsigned long handle; + }; + struct zspage *zspage; +}; +#define ZPDESC_MATCH(pg, zp) \ + static_assert(offsetof(struct page, pg) =3D=3D offsetof(struct zpdesc, zp= )) + +ZPDESC_MATCH(flags, flags); +ZPDESC_MATCH(lru, lru); +ZPDESC_MATCH(index, next); +ZPDESC_MATCH(index, handle); +ZPDESC_MATCH(private, zspage); +#undef ZPDESC_MATCH +static_assert(sizeof(struct zpdesc) <=3D sizeof(struct page)); + +#define zpdesc_page(zp) (_Generic((zp), \ + const struct zpdesc *: (const struct page *)(zp), \ + struct zpdesc *: (struct page *)(zp))) + +#define zpdesc_folio(zp) (_Generic((zp), \ + const struct zpdesc *: (const struct folio *)(zp), \ + struct zpdesc *: (struct folio *)(zp))) + +#define page_zpdesc(p) (_Generic((p), \ + const struct page *: (const struct zpdesc *)(p), \ + struct page *: (struct zpdesc *)(p))) + +#endif diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index fec1a39e5bbe..67bb80b7413a 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -13,17 +13,17 @@ =20 /* * Following is how we use various fields and flags of underlying - * struct page(s) to form a zspage. + * struct zpdesc(page) to form a zspage. * - * Usage of struct page fields: - * page->private: points to zspage - * page->index: links together all component pages of a zspage + * Usage of struct zpdesc fields: + * zpdesc->zspage: points to zspage + * zpdesc->next: links together all component pages of a zspage * For the huge page, this is always 0, so we use this field * to store handle. * page->page_type: PG_zsmalloc, lower 16 bit locate the first object * offset in a subpage of a zspage * - * Usage of struct page flags: + * Usage of struct zpdesc(page) flags: * PG_private: identifies the first component page * PG_owner_priv_1: identifies the huge component page * @@ -64,6 +64,7 @@ #include #include #include +#include "zpdesc.h" =20 #define ZSPAGE_MAGIC 0x58 =20 @@ -253,7 +254,7 @@ struct zspage { }; unsigned int inuse; unsigned int freeobj; - struct page *first_page; + struct zpdesc *first_zpdesc; struct list_head list; /* fullness list */ struct zs_pool *pool; rwlock_t lock; @@ -448,7 +449,7 @@ static inline void mod_zspage_inuse(struct zspage *zspa= ge, int val) =20 static inline struct page *get_first_page(struct zspage *zspage) { - struct page *first_page =3D zspage->first_page; + struct page *first_page =3D zpdesc_page(zspage->first_zpdesc); =20 VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); return first_page; @@ -948,7 +949,7 @@ static void create_page_chain(struct size_class *class,= struct zspage *zspage, set_page_private(page, (unsigned long)zspage); page->index =3D 0; if (i =3D=3D 0) { - zspage->first_page =3D page; + zspage->first_zpdesc =3D page_zpdesc(page); SetPagePrivate(page); if (unlikely(class->objs_per_zspage =3D=3D 1 && class->pages_per_zspage =3D=3D 1)) @@ -1325,7 +1326,7 @@ static unsigned long obj_malloc(struct zs_pool *pool, link->handle =3D handle; else /* record handle to page->index */ - zspage->first_page->index =3D handle; + zspage->first_zpdesc->handle =3D handle; =20 kunmap_atomic(vaddr); mod_zspage_inuse(zspage, 1); --=20 2.43.0