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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AC0DCC41514 for ; Wed, 31 Jul 2019 23:06:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79CC4216C8 for ; Wed, 31 Jul 2019 23:06:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uwHmDfLq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730585AbfGaXGs (ORCPT ); Wed, 31 Jul 2019 19:06:48 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:45978 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725793AbfGaXGr (ORCPT ); Wed, 31 Jul 2019 19:06:47 -0400 Received: by mail-pg1-f196.google.com with SMTP id o13so32798537pgp.12 for ; Wed, 31 Jul 2019 16:06:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=049t7JxvZTTTjSKZ1poKKugPV6OSOy/7hb4LReWg88o=; b=uwHmDfLq0KdRRrIpXBZ7eh2E2Di7CZCsc7Q4ENgQh9pTHk3z1+zjKf7oTZBOymsGIS mnqtFBhdLcW/vLb9BKhOsF1r8tKUhH2SZyNqHdaOOW4EhxFLBdByJFXqYtU3rct1sR8x DQ4pUSojQb0BZPBAzWpkCE8DfLkjinN+3dMTHyT3vVnRNHra0YbWT/Gfw69nX8iJwdAi Lseiy9WWaE54CJg+RUrgeDBd7td8wHWw3TPatkiaa6sOTqPXRZqBLfjOGpLkCJMfxHJm RnJ2r6c81O9ZleTk+YaUC2O/dZPpRL18733LECbGGYlK9s72ycaGCqYaL4b1Gc0DEXYt w3Ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=049t7JxvZTTTjSKZ1poKKugPV6OSOy/7hb4LReWg88o=; b=P744u7Z1ABeaeuD/aAEjzTSU5ptREsuilasVpvKPxBL2WskJIsr8sPEdh9RSuuUj+o Fyo4ITWqLhWfg/Z9r375Wjk4SuMKi3LeLDdL1DUdfmXfgtqe8WO+dS+g5dH16SCCz8ey tGZt+fa5VmG7HiVBZb1ME/hbqgG5Bu8+fDKRUoyiAaNjiJIlVKN6s5+7zWq9hbV/wEil aALG0tXRlqyAeuXVQ5oZSNVfornjvSVoQM+uOQApnbjZA7AjdSKFP4F6HGs8UsJDqw+L HzsqMnIGGbj435Er/fOXUPX3XYgGReczNPHe/iXLVxyQ/hlygeL14w2+0m+3PYztEcP9 pgKg== X-Gm-Message-State: APjAAAXpFJGudcz4It5vDNKhA+fvdiXHt7mTNcaawjzjCCN18L6/5iML wdR3szuXygJwArLa8Ubr6v+D7z+z X-Google-Smtp-Source: APXvYqxp2QruKLqLy7023Eu9qytL/7DmpVnAriEavxnn4B49X9D6LXrlXTRhvHAAadOvWaRD1E0HQA== X-Received: by 2002:a62:f20b:: with SMTP id m11mr50144512pfh.125.1564614407259; Wed, 31 Jul 2019 16:06:47 -0700 (PDT) Received: from rashmica.ozlabs.ibm.com ([122.99.82.10]) by smtp.googlemail.com with ESMTPSA id p187sm110668968pfg.89.2019.07.31.16.06.43 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 31 Jul 2019 16:06:46 -0700 (PDT) Message-ID: <4ddee0dd719abd50350f997b8089fa26f6004c0c.camel@gmail.com> Subject: Re: [PATCH v2 0/5] Allocate memmap from hotadded memory From: Rashmica Gupta To: Michal Hocko Cc: Oscar Salvador , David Hildenbrand , Andrew Morton , Dan Williams , pasha.tatashin@soleen.com, Jonathan.Cameron@huawei.com, anshuman.khandual@arm.com, Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Thu, 01 Aug 2019 09:06:40 +1000 In-Reply-To: <20190731120859.GJ9330@dhcp22.suse.cz> References: <20190625075227.15193-1-osalvador@suse.de> <2ebfbd36-11bd-9576-e373-2964c458185b@redhat.com> <20190626080249.GA30863@linux> <2750c11a-524d-b248-060c-49e6b3eb8975@redhat.com> <20190626081516.GC30863@linux> <887b902e-063d-a857-d472-f6f69d954378@redhat.com> <9143f64391d11aa0f1988e78be9de7ff56e4b30b.camel@gmail.com> <20190702074806.GA26836@linux> <20190731120859.GJ9330@dhcp22.suse.cz> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-07-31 at 14:08 +0200, Michal Hocko wrote: > On Tue 02-07-19 18:52:01, Rashmica Gupta wrote: > [...] > > > 2) Why it was designed, what is the goal of the interface? > > > 3) When it is supposed to be used? > > > > > > > > There is a hardware debugging facility (htm) on some power chips. > > To use > > this you need a contiguous portion of memory for the output to be > > dumped > > to - and we obviously don't want this memory to be simultaneously > > used by > > the kernel. > > How much memory are we talking about here? Just curious. >From what I've seen a couple of GB per node, so maybe 2-10GB total. 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[209.85.220.65]) by mx.google.com with SMTPS id y131sor50881204pfb.27.2019.07.31.16.06.47 for (Google Transport Security); Wed, 31 Jul 2019 16:06:47 -0700 (PDT) Received-SPF: pass (google.com: domain of rashmica.g@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=uwHmDfLq; spf=pass (google.com: domain of rashmica.g@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=rashmica.g@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=049t7JxvZTTTjSKZ1poKKugPV6OSOy/7hb4LReWg88o=; b=uwHmDfLq0KdRRrIpXBZ7eh2E2Di7CZCsc7Q4ENgQh9pTHk3z1+zjKf7oTZBOymsGIS mnqtFBhdLcW/vLb9BKhOsF1r8tKUhH2SZyNqHdaOOW4EhxFLBdByJFXqYtU3rct1sR8x DQ4pUSojQb0BZPBAzWpkCE8DfLkjinN+3dMTHyT3vVnRNHra0YbWT/Gfw69nX8iJwdAi Lseiy9WWaE54CJg+RUrgeDBd7td8wHWw3TPatkiaa6sOTqPXRZqBLfjOGpLkCJMfxHJm RnJ2r6c81O9ZleTk+YaUC2O/dZPpRL18733LECbGGYlK9s72ycaGCqYaL4b1Gc0DEXYt w3Ng== X-Google-Smtp-Source: APXvYqxp2QruKLqLy7023Eu9qytL/7DmpVnAriEavxnn4B49X9D6LXrlXTRhvHAAadOvWaRD1E0HQA== X-Received: by 2002:a62:f20b:: with SMTP id m11mr50144512pfh.125.1564614407259; Wed, 31 Jul 2019 16:06:47 -0700 (PDT) Received: from rashmica.ozlabs.ibm.com ([122.99.82.10]) by smtp.googlemail.com with ESMTPSA id p187sm110668968pfg.89.2019.07.31.16.06.43 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 31 Jul 2019 16:06:46 -0700 (PDT) Message-ID: <4ddee0dd719abd50350f997b8089fa26f6004c0c.camel@gmail.com> Subject: Re: [PATCH v2 0/5] Allocate memmap from hotadded memory From: Rashmica Gupta To: Michal Hocko Cc: Oscar Salvador , David Hildenbrand , Andrew Morton , Dan Williams , pasha.tatashin@soleen.com, Jonathan.Cameron@huawei.com, anshuman.khandual@arm.com, Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Thu, 01 Aug 2019 09:06:40 +1000 In-Reply-To: <20190731120859.GJ9330@dhcp22.suse.cz> References: <20190625075227.15193-1-osalvador@suse.de> <2ebfbd36-11bd-9576-e373-2964c458185b@redhat.com> <20190626080249.GA30863@linux> <2750c11a-524d-b248-060c-49e6b3eb8975@redhat.com> <20190626081516.GC30863@linux> <887b902e-063d-a857-d472-f6f69d954378@redhat.com> <9143f64391d11aa0f1988e78be9de7ff56e4b30b.camel@gmail.com> <20190702074806.GA26836@linux> <20190731120859.GJ9330@dhcp22.suse.cz> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 2019-07-31 at 14:08 +0200, Michal Hocko wrote: > On Tue 02-07-19 18:52:01, Rashmica Gupta wrote: > [...] > > > 2) Why it was designed, what is the goal of the interface? > > > 3) When it is supposed to be used? > > > > > > > > There is a hardware debugging facility (htm) on some power chips. > > To use > > this you need a contiguous portion of memory for the output to be > > dumped > > to - and we obviously don't want this memory to be simultaneously > > used by > > the kernel. > > How much memory are we talking about here? Just curious. >From what I've seen a couple of GB per node, so maybe 2-10GB total.