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Tue, 13 Aug 2024 08:42:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723538549; bh=LliY088wtfrFrkEgAuCs8QB3X7nNhs8HeH2Nz6Y9mEw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nmh3whJ7Km/PF9o1d6vjECtU9Q80lnjNCgYP9PH9/NyPaAXEUHXt67dUXagF2kxJN iRDLDAo3ER+9SiJxE5n9vGjNdT/ystypfHXN7rz2cDxps/B76wJ1GXiO9x7Svsqary uIeHzEY7e575DxDpwD7wIG5T4JVhCNm2AuRWmHrw4z+gMy9A7dSCRxFv7E1XjDJFyl 4aJmKyjQ4Miw0W6rZon7W/bWTIIPlWusKE7wnMSAoqCIsVfv2RBunbaMWUR2kJNKLl G5Ckm23NitU1OBGjeMAD202eP27uIhCa7dduav/25zMWGJX2zZuJJuyj0w8f4xmKiU yrOb2BecslR9g== 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, Yosry Ahmed , nphamcs@gmail.com Cc: Alex Shi Subject: [PATCH v6 21/21] mm/zsmalloc: update comments for page->zpdesc changes Date: Tue, 13 Aug 2024 16:46:07 +0800 Message-ID: <20240813084611.4122571-22-alexs@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240813084611.4122571-1-alexs@kernel.org> References: <20240813084611.4122571-1-alexs@kernel.org> MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: EAE8D40018 X-Stat-Signature: h7a4w1tj6rhkzkyyzfx79f4wmx5gwefx X-Rspam-User: X-HE-Tag: 1723538552-867904 X-HE-Meta: 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 3e9UMyJg NQpNtleS9zYKJfBS1nmz+wfhboZ4zVr7cle6myQ75xhMUGFSBZZG1g978aEuUx6NKjo+PfT1AGC0TWsIQl4i/xtn6D8hb4l4zRISYcucCR3unvsjov3uIhzBED5kgfwNFDGDpgQrGm1y+Fxu0cP9dCHofbqAaQuFpCHRNJqz21dZNblMacO52TEWC0nnsRHKz/IFlELsGQ0/x06ObjhMGXTF8Z9bcRCqunSuQEEx6yVH8i5TDDm1Aw2uzZS2jFE4z9xTMrZXnETq3BO/87/cnx6KpkvIt/thpfwsWa9hD03ejp1m12S0E/7xEUg== 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: From: Alex Shi After the page to zpdesc conversion, there still left few comments or function named with page not zpdesc, let's update the comments and rename function create_page_chain() as create_zpdesc_chain(). Signed-off-by: Alex Shi --- mm/zsmalloc.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 3dbe6bfa656b..37619f4b074b 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -17,14 +17,16 @@ * * Usage of struct zpdesc fields: * zpdesc->zspage: points to zspage - * zpdesc->next: links together all component pages of a zspage + * zpdesc->next: links together all component zpdescs of a zspage * For the huge page, this is always 0, so we use this field * to store handle. * zpdesc->first_obj_offset: PG_zsmalloc, lower 16 bit locate the first * object offset in a subpage of a zspage * * Usage of struct zpdesc(page) flags: - * PG_private: identifies the first component page + * PG_private: identifies the first component zpdesc + * PG_lock: lock all component zpdescs for a zspage free, serialize with + * migration */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -191,7 +193,10 @@ struct size_class { */ int size; int objs_per_zspage; - /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */ + /* + * Number of PAGE_SIZE sized zpdescs/pages to combine to + * form a 'zspage' + */ int pages_per_zspage; unsigned int index; @@ -907,7 +912,7 @@ static void free_zspage(struct zs_pool *pool, struct size_class *class, /* * Since zs_free couldn't be sleepable, this function cannot call - * lock_page. The page locks trylock_zspage got will be released + * lock_page. The zpdesc locks trylock_zspage got will be released * by __free_zspage. */ if (!trylock_zspage(zspage)) { @@ -964,7 +969,7 @@ static void init_zspage(struct size_class *class, struct zspage *zspage) set_freeobj(zspage, 0); } -static void create_page_chain(struct size_class *class, struct zspage *zspage, +static void create_zpdesc_chain(struct size_class *class, struct zspage *zspage, struct zpdesc *zpdescs[]) { int i; @@ -973,9 +978,9 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage, int nr_zpdescs = class->pages_per_zspage; /* - * Allocate individual pages and link them together as: - * 1. all pages are linked together using zpdesc->next - * 2. each sub-page point to zspage using zpdesc->zspage + * Allocate individual zpdescs and link them together as: + * 1. all zpdescs are linked together using zpdesc->next + * 2. each sub-zpdesc point to zspage using zpdesc->zspage * * we set PG_private to identify the first zpdesc (i.e. no other zpdesc * has this flag set). @@ -1033,7 +1038,7 @@ static struct zspage *alloc_zspage(struct zs_pool *pool, zpdescs[i] = zpdesc; } - create_page_chain(class, zspage, zpdescs); + create_zpdesc_chain(class, zspage, zpdescs); init_zspage(class, zspage); zspage->pool = pool; zspage->class = class->index; @@ -1360,7 +1365,7 @@ static unsigned long obj_malloc(struct zs_pool *pool, /* record handle in the header of allocated chunk */ link->handle = handle | OBJ_ALLOCATED_TAG; else - /* record handle to page->index */ + /* record handle to zpdesc->handle */ zspage->first_zpdesc->handle = handle | OBJ_ALLOCATED_TAG; kunmap_atomic(vaddr); @@ -1693,19 +1698,19 @@ static int putback_zspage(struct size_class *class, struct zspage *zspage) #ifdef CONFIG_COMPACTION /* * To prevent zspage destroy during migration, zspage freeing should - * hold locks of all pages in the zspage. + * hold locks of all component zpdesc in the zspage. */ static void lock_zspage(struct zspage *zspage) { struct zpdesc *curr_zpdesc, *zpdesc; /* - * Pages we haven't locked yet can be migrated off the list while we're + * Zpdesc we haven't locked yet can be migrated off the list while we're * trying to lock them, so we need to be careful and only attempt to - * lock each page under migrate_read_lock(). Otherwise, the page we lock - * may no longer belong to the zspage. This means that we may wait for - * the wrong page to unlock, so we must take a reference to the page - * prior to waiting for it to unlock outside migrate_read_lock(). + * lock each zpdesc under migrate_read_lock(). Otherwise, the zpdesc we + * lock may no longer belong to the zspage. This means that we may wait + * for the wrong zpdesc to unlock, so we must take a reference to the + * zpdesc prior to waiting for it to unlock outside migrate_read_lock(). */ while (1) { migrate_read_lock(zspage); @@ -1780,7 +1785,7 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage, idx++; } while ((zpdesc = get_next_zpdesc(zpdesc)) != NULL); - create_page_chain(class, zspage, zpdescs); + create_zpdesc_chain(class, zspage, zpdescs); first_obj_offset = get_first_obj_offset(oldzpdesc); set_first_obj_offset(newzpdesc, first_obj_offset); if (unlikely(ZsHugePage(zspage))) @@ -1791,8 +1796,8 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage, static bool zs_page_isolate(struct page *page, isolate_mode_t mode) { /* - * Page is locked so zspage couldn't be destroyed. For detail, look at - * lock_zspage in free_zspage. + * Page/zpdesc is locked so zspage couldn't be destroyed. For detail, + * look at lock_zspage in free_zspage. */ VM_BUG_ON_PAGE(PageIsolated(page), page); @@ -1819,7 +1824,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page, /* We're committed, tell the world that this is a Zsmalloc page. */ __zpdesc_set_zsmalloc(newzpdesc); - /* The page is locked, so this pointer must remain valid */ + /* The zpdesc/page is locked, so this pointer must remain valid */ zspage = get_zspage(zpdesc); pool = zspage->pool; @@ -1892,7 +1897,7 @@ static const struct movable_operations zsmalloc_mops = { }; /* - * Caller should hold page_lock of all pages in the zspage + * Caller should hold zpdesc locks of all in the zspage * In here, we cannot use zspage meta data. */ static void async_free_zspage(struct work_struct *work)