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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 5E00AC433DB for ; Mon, 25 Jan 2021 21:38:37 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 1B59B22582 for ; Mon, 25 Jan 2021 21:38:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B59B22582 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id DA926100EBBD5; Mon, 25 Jan 2021 13:38:36 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=rppt@kernel.org; receiver= Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 60BE6100EBBCD for ; Mon, 25 Jan 2021 13:38:34 -0800 (PST) Received: by mail.kernel.org (Postfix) with ESMTPSA id A683E2083E; Mon, 25 Jan 2021 21:38:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611610714; bh=oBbSa76JFc7v8+y55SX0g1Mr9sPSRsNOv4tmWq7xrRA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ubeXULCeE5ESYXoKbbpQZvbpm7KD3rJtLMZd3bLMpG+Yf8ZlUgaes9e13MakOokA9 iEgnWl6tWG8fgiW+VJGsU1Vz4qkDtXaocuKZT5gFf6r99ZgN3QhYKOTmMnfoGOogzo zlSt15bli+VWxniwjlxtECCstKhhIQyCjc9aSnUV55QlpbsGcamdfknFZPmcXMuxob G02UJe9Qaa5X7Qu+hPXzpNUvjCDYeTaIEq+run7rkZRwSUoqDGVquo06czJpfyCKh6 lYHTox8ewX/SByv9aTWjggJVW9TsgcM9496MPOix7WOWD0WDa1bKzdlfYuPxgdGr6W 86DtTT5jWaIDg== Date: Mon, 25 Jan 2021 23:38:17 +0200 From: Mike Rapoport To: Michal Hocko Subject: Re: [PATCH v16 08/11] secretmem: add memcg accounting Message-ID: <20210125213817.GM6332@kernel.org> References: <20210121122723.3446-1-rppt@kernel.org> <20210121122723.3446-9-rppt@kernel.org> <20210125165451.GT827@dhcp22.suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210125165451.GT827@dhcp22.suse.cz> Message-ID-Hash: VONGQZ7UYDZUAQDRFK6OCJYGJRUOSBGL X-Message-ID-Hash: VONGQZ7UYDZUAQDRFK6OCJYGJRUOSBGL X-MailFrom: rppt@kernel.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer , Palmer Dabbelt X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, Jan 25, 2021 at 05:54:51PM +0100, Michal Hocko wrote: > On Thu 21-01-21 14:27:20, Mike Rapoport wrote: > > From: Mike Rapoport > > > > Account memory consumed by secretmem to memcg. The accounting is updated > > when the memory is actually allocated and freed. > > What does this mean? That means that the accounting is updated when secretmem does cma_alloc() and cma_relase(). > What are the lifetime rules? Hmm, what do you mean by lifetime rules? > [...] > > > +static int secretmem_account_pages(struct page *page, gfp_t gfp, int order) > > +{ > > + int err; > > + > > + err = memcg_kmem_charge_page(page, gfp, order); > > + if (err) > > + return err; > > + > > + /* > > + * seceremem caches are unreclaimable kernel allocations, so treat > > + * them as unreclaimable slab memory for VM statistics purposes > > + */ > > + mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B, > > + PAGE_SIZE << order); > > A lot of memcg accounted memory is not reclaimable. Why do you abuse > SLAB counter when this is not a slab owned memory? Why do you use the > kmem accounting API when __GFP_ACCOUNT should give you the same without > this details? I cannot use __GFP_ACCOUNT because cma_alloc() does not use gfp. Besides, kmem accounting with __GFP_ACCOUNT does not seem to update stats and there was an explicit request for statistics: https://lore.kernel.org/lkml/CALo0P13aq3GsONnZrksZNU9RtfhMsZXGWhK1n=xYJWQizCd4Zw@mail.gmail.com/ As for (ab)using NR_SLAB_UNRECLAIMABLE_B, as it was already discussed here: https://lore.kernel.org/lkml/20201129172625.GD557259@kernel.org/ I think that a dedicated stats counter would be too much at the moment and NR_SLAB_UNRECLAIMABLE_B is the only explicit stat for unreclaimable memory. -- Sincerely yours, Mike. _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org