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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 EE8B8C0650E for ; Mon, 1 Jul 2019 10:59:13 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 7DD2D20673 for ; Mon, 1 Jul 2019 10:59:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DD2D20673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45ckrv20QMzDqTj for ; Mon, 1 Jul 2019 20:59:11 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=aneesh.kumar@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45ckpt4pjtzDqT4 for ; Mon, 1 Jul 2019 20:57:25 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x61Av7M1034905 for ; Mon, 1 Jul 2019 06:57:21 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tfgnmrswm-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 01 Jul 2019 06:57:20 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 1 Jul 2019 11:57:15 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x61AvFCE46137400 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 1 Jul 2019 10:57:15 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EE5DB52050; Mon, 1 Jul 2019 10:57:14 +0000 (GMT) Received: from skywalker.linux.ibm.com (unknown [9.85.81.231]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id BB4865204F; Mon, 1 Jul 2019 10:57:13 +0000 (GMT) X-Mailer: emacs 26.2 (via feedmail 11-beta-1 I) From: "Aneesh Kumar K.V" To: "Oliver O'Halloran" Subject: Re: [PATCH] powerpc/mm/nvdimm: Add an informative message if we fail to allocate altmap block In-Reply-To: References: <20190629073813.12973-1-aneesh.kumar@linux.ibm.com> Date: Mon, 01 Jul 2019 16:27:12 +0530 MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 x-cbid: 19070110-0012-0000-0000-0000032E23E1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19070110-0013-0000-0000-000021676CE6 Message-Id: <874l46nhtj.fsf@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-01_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907010136 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: linuxppc-dev , Paul Mackerras , Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" "Oliver O'Halloran" writes: > On Sat, Jun 29, 2019 at 5:39 PM Aneesh Kumar K.V > wrote: >> >> Allocation from altmap area can fail based on vmemmap page size used. Add kernel >> info message to indicate the failure. That allows the user to identify whether they >> are really using persistent memory reserved space for per-page metadata. >> >> The message looks like: >> [ 136.587212] altmap block allocation failed, falling back to system memory >> >> Signed-off-by: Aneesh Kumar K.V >> --- >> arch/powerpc/mm/init_64.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c >> index a4e17a979e45..57c0573650dc 100644 >> --- a/arch/powerpc/mm/init_64.c >> +++ b/arch/powerpc/mm/init_64.c >> @@ -194,8 +194,12 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, >> * fail due to alignment issues when using 16MB hugepages, so >> * fall back to system memory if the altmap allocation fail. >> */ >> - if (altmap) >> + if (altmap) { >> p = altmap_alloc_block_buf(page_size, altmap); >> + if (!p) > >> + pr_info("altmap block allocation failed, " \ >> + "falling back to system memory"); > > I think this is kind of misleading. If you're mapping a large amount > of memory you can have most of the vmemmap backing allocated from the > altmap and one extra block allocated from normal memory. E.g. If you > have 32MB of altmap space, one 16MB block will be allocated from the > altmap, but the 2nd 16MB block is probably unusable due to the > reserved pages at the start of the altmap. Maybe this should be a > pr_debug() so it's only printed along with the "vmemmap_populate ..." > message above? Will switch to pr_debug. What I really wanted was an indication of which pfn device failed to allocate per page meata data in the device. But we really don't have device details here and we don't end up calling this function if there is already a 16MB mapping in DRAM for this area. > > Also, isn't kernel style to keep printf()s, even long ones, on one line? I was not sure. It do print to kernel log in one line. -aneesh