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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 E75EDC3A5A1 for ; Wed, 21 Aug 2019 19:12:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B4115216F4 for ; Wed, 21 Aug 2019 19:12:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4115216F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4503B6B029A; Wed, 21 Aug 2019 15:12:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4017F6B029B; Wed, 21 Aug 2019 15:12:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2F0A96B029C; Wed, 21 Aug 2019 15:12:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 0B2C26B029A for ; Wed, 21 Aug 2019 15:12:41 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id B51FD180AD801 for ; Wed, 21 Aug 2019 19:12:40 +0000 (UTC) X-FDA: 75847381680.16.rock94_6e97291bcae0a X-HE-Tag: rock94_6e97291bcae0a X-Filterd-Recvd-Size: 8329 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Wed, 21 Aug 2019 19:12:39 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AB93B3082128; Wed, 21 Aug 2019 19:12:38 +0000 (UTC) Received: from [10.36.118.29] (unknown [10.36.118.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1086A46; Wed, 21 Aug 2019 19:12:34 +0000 (UTC) Subject: Re: [PATCH v2] mm/balloon_compaction: Informative allocation warnings To: Nadav Amit Cc: "Michael S. Tsirkin" , Jason Wang , "virtualization@lists.linux-foundation.org" , Linux-MM , "linux-kernel@vger.kernel.org" References: <20190821094159.40795-1-namit@vmware.com> <75ff92c2-7ae2-c4a6-cd1f-44741e29d20e@redhat.com> <4E10A342-9A51-4C1F-8E5A-8005AACEF4CE@vmware.com> <497b1189-8e1d-2926-ee5e-9077fcceb04b@redhat.com> <36AC2460-9E88-4BAF-B793-A14A00E41617@vmware.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <3873b6ab-de6d-cac2-90e8-541fe86e2005@redhat.com> Date: Wed, 21 Aug 2019 21:12:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <36AC2460-9E88-4BAF-B793-A14A00E41617@vmware.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Wed, 21 Aug 2019 19:12:38 +0000 (UTC) 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 21.08.19 21:10, Nadav Amit wrote: >> On Aug 21, 2019, at 12:06 PM, David Hildenbrand wrote: >> >> On 21.08.19 20:59, Nadav Amit wrote: >>>> On Aug 21, 2019, at 11:57 AM, David Hildenbrand wrote: >>>> >>>> On 21.08.19 11:41, Nadav Amit wrote: >>>>> There is no reason to print generic warnings when balloon memory >>>>> allocation fails, as failures are expected and can be handled >>>>> gracefully. Since VMware balloon now uses balloon-compaction >>>>> infrastructure, and suppressed these warnings before, it is also >>>>> beneficial to suppress these warnings to keep the same behavior that the >>>>> balloon had before. >>>>> >>>>> Since such warnings can still be useful to indicate that the balloon is >>>>> over-inflated, print more informative and less frightening warning if >>>>> allocation fails instead. >>>>> >>>>> Cc: David Hildenbrand >>>>> Cc: Jason Wang >>>>> Signed-off-by: Nadav Amit >>>>> >>>>> --- >>>>> >>>>> v1->v2: >>>>> * Print informative warnings instead suppressing [David] >>>>> --- >>>>> mm/balloon_compaction.c | 7 ++++++- >>>>> 1 file changed, 6 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c >>>>> index 798275a51887..0c1d1f7689f0 100644 >>>>> --- a/mm/balloon_compaction.c >>>>> +++ b/mm/balloon_compaction.c >>>>> @@ -124,7 +124,12 @@ EXPORT_SYMBOL_GPL(balloon_page_list_dequeue); >>>>> struct page *balloon_page_alloc(void) >>>>> { >>>>> struct page *page = alloc_page(balloon_mapping_gfp_mask() | >>>>> - __GFP_NOMEMALLOC | __GFP_NORETRY); >>>>> + __GFP_NOMEMALLOC | __GFP_NORETRY | >>>>> + __GFP_NOWARN); >>>>> + >>>>> + if (!page) >>>>> + pr_warn_ratelimited("memory balloon: memory allocation failed"); >>>>> + >>>>> return page; >>>>> } >>>>> EXPORT_SYMBOL_GPL(balloon_page_alloc); >>>> >>>> Not sure if "memory balloon" is the right wording. hmmm. >>>> >>>> Acked-by: David Hildenbrand >>> >>> Do you have a better suggestion? >> >> Not really - that's why I ack'ed :) >> >> However, thinking about it - what about moving the check + print to the >> caller and then using dev_warn... or sth. like simple "virtio_balloon: >> ..." ? You can then drop the warning for vmware balloon if you feel like >> not needing it. > > Actually, there is already a warning that is printed by the virtue_balloon > in fill_balloon(): > > struct page *page = balloon_page_alloc(); > > if (!page) { > dev_info_ratelimited(&vb->vdev->dev, > "Out of puff! Can't get %u pages\n", > VIRTIO_BALLOON_PAGES_PER_PAGE); > /* Sleep for at least 1/5 of a second before retry. */ > msleep(200); > break; > } > > So are you ok with going back to v1? > Whoops, I missed that - sorry - usually the warnings scream louder at me :D Yes, v1 is fine with me! -- Thanks, David / dhildenb