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 X-Spam-Level: X-Spam-Status: No, score=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9C65C433E6 for ; Wed, 24 Mar 2021 19:05:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8273761A21 for ; Wed, 24 Mar 2021 19:05:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237691AbhCXTFG (ORCPT ); Wed, 24 Mar 2021 15:05:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237726AbhCXTEs (ORCPT ); Wed, 24 Mar 2021 15:04:48 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79668C061763 for ; Wed, 24 Mar 2021 12:04:47 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id x126so18049252pfc.13 for ; Wed, 24 Mar 2021 12:04:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :mime-version; bh=A6Nc9aMcq7+EQ6dTXC6K5AV/+r3Lw/sToxnXYeBBrHg=; b=TG9ZdBbsC14dV/G8r6EC4apbfUONcaQ+4FikYf7V3wU5EHgnpwXTa3pqy3t5awCWPA bq2xeScTiikkcJ5f8Ku/xPhKhNpsgodybG4FwG2kzuegE6NRv6EhgjwhRTgzWnNadewf K1/UVIuvSI12YfcVELAtScF+GScUZqodT5LIjtA1conVZSTrXUX8BXpitefSL0a1hcW4 14hRGiu7qxZUpvKSrKx1EScWSeRjO6ERDl6vnUUmd3pmc6m/kcMxM2oKzRKCOrXtfGkd dphpm8O9U8nk/NnvzMMKXVQ2ld/NyWa0RNMhAwTXEJCCnor3UT8wvHN6gTA+OuWKSBJd Utrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=A6Nc9aMcq7+EQ6dTXC6K5AV/+r3Lw/sToxnXYeBBrHg=; b=XY8DLv5LzGnnlvJbphGhShFXNrEesmv89baIMHigp35QQhkS4/gfWaBl0m5u44hXGq wZuYxcyEwOl62o0xuVOv5uYClxlFFBUZouxHLVdG2w+SVBPkiqaEk3LIkHZYriWFFt5/ 97S5v6rcFnPFJpKXb03IFup24DKeMiSjo8RnYBNqAinTxwR/XfcZt+HpKC6eRVaKn9mW ddnoqiS7/3SYSrLfakiy6S6OLelowjxTVFxlVMenPwSyVMdFjHW24LwBjYOX9d/hZpLl OgwEorwKyINJo0way0o6TsQa6JfjBf0dpDScfISAid3J08gdnRiWbCvrDckEFrRupBQN 5PYw== X-Gm-Message-State: AOAM532u2e6Oto/MEVjcM+AXY8PSYf3Vem6/2/psuyAYH7JUmQCM0CL6 AKWaj99ixWTiJgizy3+ApSwMiA== X-Google-Smtp-Source: ABdhPJxlGHQwXuLGkqxg81umxZd6iX089au/ES9PkkTU1JTdQlDXHcccm+lnM11MQ123uHAXPysWcA== X-Received: by 2002:a63:d449:: with SMTP id i9mr4121104pgj.227.1616612686794; Wed, 24 Mar 2021 12:04:46 -0700 (PDT) Received: from [2620:15c:17:3:4192:718f:4827:be5] ([2620:15c:17:3:4192:718f:4827:be5]) by smtp.gmail.com with ESMTPSA id y24sm3225118pfn.213.2021.03.24.12.04.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Mar 2021 12:04:45 -0700 (PDT) Date: Wed, 24 Mar 2021 12:04:45 -0700 (PDT) From: David Rientjes To: "Matthew Wilcox (Oracle)" cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Christoph Lameter , Pekka Enberg , Joonsoo Kim , Vlastimil Babka , Uladzislau Rezki , Nicholas Piggin Subject: Re: [PATCH v2 3/4] mm/vmalloc: Use kvmalloc to allocate the table of pages In-Reply-To: <20210324150518.2734402-4-willy@infradead.org> Message-ID: <9e3d5e8a-4e47-d29a-8474-925036d8e5b@google.com> References: <20210324150518.2734402-1-willy@infradead.org> <20210324150518.2734402-4-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 24 Mar 2021, Matthew Wilcox (Oracle) wrote: > If we're trying to allocate 4MB of memory, the table will be 8KiB in size > (1024 pointers * 8 bytes per pointer), which can usually be satisfied > by a kmalloc (which is significantly faster). Instead of changing this > open-coded implementation, just use kvmalloc(). > > This improves the allocation speed of vmalloc(4MB) by approximately > 5% in our benchmark. It's still dominated by the 1024 calls to > alloc_pages_node(), which will be the subject of a later patch. > > Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Rientjes