From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id 7B13F6B025F for ; Mon, 14 Aug 2017 05:56:48 -0400 (EDT) Received: by mail-pg0-f69.google.com with SMTP id r133so126855766pgr.6 for ; Mon, 14 Aug 2017 02:56:48 -0700 (PDT) Received: from xiaomi.com (outboundhk.mxmail.xiaomi.com. [207.226.244.125]) by mx.google.com with ESMTPS id g6si4386131plj.244.2017.08.14.02.56.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 14 Aug 2017 02:56:47 -0700 (PDT) From: Hui Zhu Subject: [PATCH v2] zsmalloc: zs_page_migrate: schedule free_work if zspage is ZS_EMPTY Date: Mon, 14 Aug 2017 17:56:30 +0800 Message-ID: <1502704590-3129-1-git-send-email-zhuhui@xiaomi.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: minchan@kernel.org, ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: teawater@gmail.com, Hui Zhu After commit e2846124f9a2 ("zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse") zs_page_migrate can handle the ZS_EMPTY zspage. But I got some false in zs_page_isolate: if (get_zspage_inuse(zspage) == 0) { spin_unlock(&class->lock); return false; } The page of this zspage was migrated in before. The reason is commit e2846124f9a2 ("zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse") just handle the "page" but not "newpage" then it keep the "newpage" with a empty zspage inside system. Root cause is zs_page_isolate remove it from ZS_EMPTY list but not call zs_page_putback "schedule_work(&pool->free_work);". Because zs_page_migrate done the job without "schedule_work(&pool->free_work);" Make this patch let zs_page_migrate wake up free_work if need. Fixes: e2846124f9a2 ("zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse") Signed-off-by: Hui Zhu --- mm/zsmalloc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 62457eb..c6cc77c 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -2035,8 +2035,17 @@ int zs_page_migrate(struct address_space *mapping, struct page *newpage, * Page migration is done so let's putback isolated zspage to * the list if @page is final isolated subpage in the zspage. */ - if (!is_zspage_isolated(zspage)) - putback_zspage(class, zspage); + if (!is_zspage_isolated(zspage)) { + /* + * Page will be freed in following part. But newpage and + * zspage will stay in system if zspage is in ZS_EMPTY + * list. So call free_work to free it. + * The page and class is locked, we cannot free zspage + * immediately so let's defer. + */ + if (putback_zspage(class, zspage) == ZS_EMPTY) + schedule_work(&pool->free_work); + } reset_page(page); put_page(page); -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org