From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 5E9156B025F for ; Tue, 15 Aug 2017 23:20:09 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id f23so36820253pgn.15 for ; Tue, 15 Aug 2017 20:20:09 -0700 (PDT) Received: from xiaomi.com (outboundhk.mxmail.xiaomi.com. [207.226.244.123]) by mx.google.com with ESMTPS id i7si6978909plk.84.2017.08.15.20.20.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 15 Aug 2017 20:20:07 -0700 (PDT) From: Hui Zhu Subject: [PATCH v3] zsmalloc: zs_page_migrate: schedule free_work if zspage is ZS_EMPTY Date: Wed, 16 Aug 2017 11:19:41 +0800 Message-ID: <1502853581-21218-1-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 [1] 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 [1] 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. [1] zsmalloc-zs_page_migrate-skip-unnecessary-loops-but-not-return-ebusy-if-zspage-is-not-inuse-fix.patch Signed-off-by: Hui Zhu --- mm/zsmalloc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 62457eb..fb99953 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -2035,8 +2035,15 @@ 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)) { + /* + * Since we allow empty zspage migration, putback of zspage + * should free empty zspage. Otherwise, it could make a leak + * until upcoming free_work is done, which isn't guaranteed. + */ + 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