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=-9.8 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_GIT 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 9962BC433FF for ; Thu, 15 Aug 2019 04:21:42 +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 22FF3208C2 for ; Thu, 15 Aug 2019 04:21:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22FF3208C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=au1.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 468CvR4l8TzDr3G for ; Thu, 15 Aug 2019 14:21:39 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=au1.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=alastair@au1.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=au1.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 468Cj33G1nzDqts for ; Thu, 15 Aug 2019 14:12:39 +1000 (AEST) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7F4CBeu060302 for ; Thu, 15 Aug 2019 00:12:36 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ucwk3vebx-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 15 Aug 2019 00:12:36 -0400 Received: from localhost by e06smtp02.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) Thu, 15 Aug 2019 05:12:30 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7F4CTtR33357896 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Aug 2019 04:12:29 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8E831A405C; Thu, 15 Aug 2019 04:12:29 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3D619A405F; Thu, 15 Aug 2019 04:12:29 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 15 Aug 2019 04:12:29 +0000 (GMT) Received: from adsilva.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 1E58BA03BC; Thu, 15 Aug 2019 14:12:28 +1000 (AEST) From: "Alastair D'Silva" To: alastair@d-silva.org Subject: [PATCH 4/6] powerpc: Chunk calls to flush_dcache_range in arch_*_memory Date: Thu, 15 Aug 2019 14:10:49 +1000 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190815041057.13627-1-alastair@au1.ibm.com> References: <20190815041057.13627-1-alastair@au1.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19081504-0008-0000-0000-000003094922 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19081504-0009-0000-0000-00004A27618B Message-Id: <20190815041057.13627-5-alastair@au1.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-08-15_02:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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=8.0.1-1906280000 definitions=main-1908150045 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: Greg Kroah-Hartman , David Hildenbrand , linux-kernel@vger.kernel.org, Nicholas Piggin , Mike Rapoport , Qian Cai , Paul Mackerras , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, Andrew Morton , Allison Randal Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Alastair D'Silva When presented with large amounts of memory being hotplugged (in my test case, ~890GB), the call to flush_dcache_range takes a while (~50 seconds), triggering RCU stalls. This patch breaks up the call into 16GB chunks, calling cond_resched() inbetween to allow the scheduler to run. Signed-off-by: Alastair D'Silva --- arch/powerpc/mm/mem.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 5400da87a804..fb0d5e9aa11b 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -104,11 +104,14 @@ int __weak remove_section_mapping(unsigned long start, unsigned long end) return -ENODEV; } +#define FLUSH_CHUNK_SIZE (16ull * 1024ull * 1024ull * 1024ull) + int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_restrictions *restrictions) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; + unsigned long i; int rc; resize_hpt_for_hotplug(memblock_phys_mem_size()); @@ -120,7 +123,11 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, start, start + size, rc); return -EFAULT; } - flush_dcache_range(start, start + size); + + for (i = 0; i < size; i += FLUSH_CHUNK_SIZE) { + flush_dcache_range(start + i, min(start + size, start + i + FLUSH_CHUNK_SIZE)); + cond_resched(); + } return __add_pages(nid, start_pfn, nr_pages, restrictions); } @@ -131,13 +138,18 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap); + unsigned long i; int ret; __remove_pages(page_zone(page), start_pfn, nr_pages, altmap); /* Remove htab bolted mappings for this section of memory */ start = (unsigned long)__va(start); - flush_dcache_range(start, start + size); + for (i = 0; i < size; i += FLUSH_CHUNK_SIZE) { + flush_dcache_range(start + i, min(start + size, start + i + FLUSH_CHUNK_SIZE)); + cond_resched(); + } + ret = remove_section_mapping(start, start + size); WARN_ON_ONCE(ret); -- 2.21.0