From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A2A6C433F5 for ; Mon, 17 Jan 2022 15:56:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240664AbiAQP4Q (ORCPT ); Mon, 17 Jan 2022 10:56:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237337AbiAQP4Q (ORCPT ); Mon, 17 Jan 2022 10:56:16 -0500 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B52B9C061574 for ; Mon, 17 Jan 2022 07:56:15 -0800 (PST) Received: by mail-lf1-x134.google.com with SMTP id m3so45271858lfu.0 for ; Mon, 17 Jan 2022 07:56:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=hLXVfGuqokAhjQPquljpv4IuCQa5SRFe/JWEcrZu/DE=; b=vWlPwu36tQDWXefh3AbPXuoJBEob07beXqKflgEp+7ZAnJW5ToHIDMHJIor8471x1c nFYXIH7cEZDVMG3Ad1Imes4RlH8Ydng8D3FkDW5MMRCK22hHEVThHKgMd85wVsb7GFYN NjF51iRPH0L/P/djgibOK7lcyHSKmyAdtxFeBBJf6FY8PPwF7Tw2bYnIWeB4Xuf5pF2j gac7TcyYTjXdsC0I9fClYQR/2Xm0R2RHuY/uCppEBkwPgNSHe4J3imjM2CYIZYS9qZe3 9CkqPiTksIsEa0tVVl3iEHdCi5/WLw/yxczM5hZetsHNeD8jc+DfAsoK7XK+iNuiLe/v ECHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hLXVfGuqokAhjQPquljpv4IuCQa5SRFe/JWEcrZu/DE=; b=OxrEaRguFL1yRAOQ/k2BnaM6ipf5QwSZpIEGrFPOQ0Dsib8IfrS4SOFbHlDSn9CwQS YT+yoew5tzvg81Z3trcz5A+pJ3LV4M0MQlOUj1AQTt5QQ+hf/SqO0UEXRCPpcCIAR0Fp yXbqvHKCsMnP9y/evy7AddSvX1E2ZOcix46YMHT5LiMF9TMcsi9J2DfUQ+znHTc3m6qq PP6k4DDxidwqpBXvBy52KpO/Yk4NF3D3qgblyGyKRfKCc3Es9t0nTgxtdF1pza5C6vUi q/6rJSPncju7hDgXWSjTuMOTpjHJmZNpBoxRMf8DQ2aNXUxakhc9AS41djbaJFVbKFOO zqTA== X-Gm-Message-State: AOAM531ahM623byvPB9biXW4MXHEdgaxY3DvJvCD9m+LGBVuN/m4RZEz 2xZUH3qJov+F91JShqsO9x0YA8fUqLR0iw== X-Google-Smtp-Source: ABdhPJz7FbfdpZdmtC5Jx84Ckv5DAebrmkY0nZUOV+wJaKhApnBN6pH5FhbND8E1a+JvKqJk7BwvRw== X-Received: by 2002:ac2:5597:: with SMTP id v23mr16906486lfg.477.1642434974035; Mon, 17 Jan 2022 07:56:14 -0800 (PST) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id k19sm1425334lfu.176.2022.01.17.07.56.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jan 2022 07:56:13 -0800 (PST) Received: by box.localdomain (Postfix, from userid 1000) id 84A7810387E; Mon, 17 Jan 2022 18:56:41 +0300 (+03) Date: Mon, 17 Jan 2022 18:56:41 +0300 From: "Kirill A. Shutemov" To: "Matthew Wilcox (Oracle)" Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 02/12] filemap: Use folio_put_refs() in filemap_free_folio() Message-ID: <20220117155641.u5ysambg72nq2p6y@box.shutemov.name> References: <20220116121822.1727633-1-willy@infradead.org> <20220116121822.1727633-3-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220116121822.1727633-3-willy@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Jan 16, 2022 at 12:18:12PM +0000, Matthew Wilcox (Oracle) wrote: > This shrinks filemap_free_folio() by 55 bytes in my .config; 24 bytes > from removing the VM_BUG_ON_FOLIO() and 31 bytes from unifying the > small/large folio paths. > > We could just use folio_ref_sub() here since the caller should hold a > reference (as the VM_BUG_ON_FOLIO() was asserting), but that's fragile. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > mm/filemap.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 2fd9b2f24025..afc8f5ca85ac 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -231,17 +231,15 @@ void __filemap_remove_folio(struct folio *folio, void *shadow) > void filemap_free_folio(struct address_space *mapping, struct folio *folio) > { > void (*freepage)(struct page *); > + int refs = 1; > > freepage = mapping->a_ops->freepage; > if (freepage) > freepage(&folio->page); > > - if (folio_test_large(folio) && !folio_test_hugetlb(folio)) { > - folio_ref_sub(folio, folio_nr_pages(folio)); > - VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio); > - } else { > - folio_put(folio); > - } > + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) > + refs = folio_nr_pages(folio); Isn't folio_test_large() check redundant? folio_nr_pages() would return 1 for non-large folio, wouldn't it? > + folio_put_refs(folio, refs); > } > > /** > -- > 2.34.1 > -- Kirill A. Shutemov