Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753304AbdHPDUQ (ORCPT ); Tue, 15 Aug 2017 23:20:16 -0400 Received: from outboundhk.mxmail.xiaomi.com ([207.226.244.125]:3834 "EHLO xiaomi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753209AbdHPDUP (ORCPT ); Tue, 15 Aug 2017 23:20:15 -0400 From: Hui Zhu To: , , , , CC: , 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> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.235.171.194] X-ClientProxiedBy: CNCAS3.mioffice.cn (10.237.8.133) To cnbox6.mioffice.cn (10.237.8.146) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1670 Lines: 48 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