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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6C48C433F5 for ; Wed, 19 Jan 2022 13:23:01 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Jf5tD08MHz3bcS for ; Thu, 20 Jan 2022 00:23:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=Cc09zlkL; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=infradead.org (client-ip=2001:8b0:10b:1236::1; helo=casper.infradead.org; envelope-from=willy@infradead.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=Cc09zlkL; dkim-atps=neutral Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Jf5sW5t88z3035 for ; Thu, 20 Jan 2022 00:22:23 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=XdBwF/RjhbWIU5o6Jz7HpuQNLjSadEnmWI/i7GCW5y0=; b=Cc09zlkLM5/Ab6cb+M3cwSs7PG huGqk0aJjbCMfwx7cGINmtqiWpkOY2MZWDoKt5SA8m0jllV54qtTq+XMW167egJYN43cWA6wmB1kT NSiw6gsSlTYaYYCOytDuMJy4dFx/vs+lSzcFzo9SptNPM3xm07UEtjKPEEPZNEk8oivGNJkbVOLpd 5E4WhC0Wuj3mmjvZ3xxOdSBKLgCT1DGgCxproJPPwnGtPAjYjE7oVogDUTUmyoh8RSR3wa/r3oLCM BAkDt2EQRiO5AzaEt+RVfOvnIvPA1+sAN1KiGh40QWfqiVw95Gyi1Xn2ZGs2zJNxe5PnYpg//wkd6 sU6IJtWA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAAua-00AsKQ-Da; Wed, 19 Jan 2022 13:22:04 +0000 Date: Wed, 19 Jan 2022 13:22:04 +0000 From: Matthew Wilcox To: Kefeng Wang Subject: Re: [PATCH v2 1/3] mm: vmalloc: Let user to control huge vmalloc default behavior Message-ID: References: <20211227145903.187152-1-wangkefeng.wang@huawei.com> <20211227145903.187152-2-wangkefeng.wang@huawei.com> <1642473992.qrnqczjfna.astroid@bobo.none> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, "H. Peter Anvin" , Dave Hansen , linux-doc@vger.kernel.org, Jonathan Corbet , linux-kernel@vger.kernel.org, Nicholas Piggin , linux-mm@kvack.org, Will Deacon , Ingo Molnar , Borislav Petkov , Catalin Marinas , Paul Mackerras , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Thomas Gleixner , linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Jan 19, 2022 at 08:57:58PM +0800, Kefeng Wang wrote: > Only parts of our products wants this feature,  we add some interfaces which > only > > alloc hugevmalloc for them, eg, > vmap_hugepage/vmalloc_hugepage/remap_vmalloc_hugepage_range.. > > for our products, but it's not the choice of most products, also add > nohugevmalloc > > for most products is expensive, so this is the reason for adding the patch. > > more config/cmdline are more flexible for test/products， But why do only some products want it? What goes wrong if all products enable it? Features should be auto-tuning, not relying on admins to understand them.