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=-4.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 3CF2BC47420 for ; Tue, 29 Sep 2020 15:16:15 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AB94B20789 for ; Tue, 29 Sep 2020 15:16:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="yExw0zMk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB94B20789 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rdg5ck8hwLSW4Yeqg4Cqf78pKi9DFW0jsHcul3eVoTU=; b=yExw0zMkJthgEZrCm5kOPPamf Q+2SR9//orlgC3jGNE6inIL+kpOi5fluL/suVeWocScfmmr+U/HV/VP9QlCRWv/f/NjACbPuqrncU lct6jjGgxFo2ZSMTZmS/95JS1PxnbZ7hPg3tNntLWnXbsYe+vW8lhFQ30uMrag38f4xPkrtOcV5qi 9yn7R3RziEekhYe7hcz/zWYA9bDzUOm7hmlLIzmMIADthLhtrUu6xnI9JhJG1QK12bjjm/Eleo1m/ 1k/yK/5cncQS+q9ZGq9jJJRGw7MscwS/5B+N4xC7lOlaMYUc5Pd0haZL/tV78Z/21sq5ZCrMhzR+F tkcJWQPkA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNHMI-000115-AJ; Tue, 29 Sep 2020 15:16:02 +0000 Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNHMC-0000zG-2k; Tue, 29 Sep 2020 15:15:56 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 191E5300F7A; Tue, 29 Sep 2020 17:15:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 004CF210E84D8; Tue, 29 Sep 2020 17:15:52 +0200 (CEST) Date: Tue, 29 Sep 2020 17:15:52 +0200 From: Peter Zijlstra To: Mike Rapoport Subject: Re: [PATCH v6 5/6] mm: secretmem: use PMD-size pages to amortize direct map fragmentation Message-ID: <20200929151552.GS2628@hirez.programming.kicks-ass.net> References: <20200924132904.1391-1-rppt@kernel.org> <20200924132904.1391-6-rppt@kernel.org> <20200925074125.GQ2628@hirez.programming.kicks-ass.net> <20200929130529.GE2142832@kernel.org> <20200929141216.GO2628@hirez.programming.kicks-ass.net> <20200929145813.GA3226834@linux.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200929145813.GA3226834@linux.ibm.com> X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , David Hildenbrand , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, Will Deacon , linux-kselftest@vger.kernel.org, "H. Peter Anvin" , Christopher Lameter , Idan Yaniv , Thomas Gleixner , Elena Reshetova , linux-arch@vger.kernel.org, Tycho Andersen , linux-nvdimm@lists.01.org, Shuah Khan , x86@kernel.org, Matthew Wilcox , Ingo Molnar , Michael Kerrisk , Arnd Bergmann , James Bottomley , Borislav Petkov , Alexander Viro , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , linux-fsdevel@vger.kernel.org, Andrew Morton , Mike Rapoport Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, Sep 29, 2020 at 05:58:13PM +0300, Mike Rapoport wrote: > On Tue, Sep 29, 2020 at 04:12:16PM +0200, Peter Zijlstra wrote: > > It will drop them down to 4k pages. Given enough inodes, and allocating > > only a single sekrit page per pmd, we'll shatter the directmap into 4k. > > Why? Secretmem allocates PMD-size page per inode and uses it as a pool > of 4K pages for that inode. This way it ensures that > __kernel_map_pages() is always called on PMD boundaries. Oh, you unmap the 2m page upfront? I read it like you did the unmap at the sekrit page alloc, not the pool alloc side of things. Then yes, but then you're wasting gobs of memory. Basically you can pin 2M per inode while only accounting a single page. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv