{"id":816465,"url":"http://patchwork.ozlabs.org/api/patches/816465/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170920201714.19817-3-pasha.tatashin@oracle.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20170920201714.19817-3-pasha.tatashin@oracle.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20170920201714.19817-3-pasha.tatashin@oracle.com/","date":"2017-09-20T20:17:04","name":"[v9,02/12] sparc64/mm: setting fields in deferred pages","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"c41caeb023d58a5b51a7dfd84842eee3a93c21cd","submitter":{"id":71010,"url":"http://patchwork.ozlabs.org/api/people/71010/?format=json","name":"Pavel Tatashin","email":"pasha.tatashin@oracle.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20170920201714.19817-3-pasha.tatashin@oracle.com/mbox/","series":[{"id":4225,"url":"http://patchwork.ozlabs.org/api/series/4225/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=4225","date":"2017-09-20T20:17:06","name":"complete deferred page initialization","version":9,"mbox":"http://patchwork.ozlabs.org/series/4225/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/816465/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816465/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xyB8x0pyLz9ryv\n\tfor ;\n\tThu, 21 Sep 2017 06:26:25 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xyB8w6gGpzDrJw\n\tfor ;\n\tThu, 21 Sep 2017 06:26:24 +1000 (AEST)","from userp1040.oracle.com (userp1040.oracle.com [156.151.31.81])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xy9zt2rbDzDqYN\n\tfor ;\n\tThu, 21 Sep 2017 06:18:34 +1000 (AEST)","from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74])\n\tby userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with\n\tESMTP id v8KKHO8J007673\n\t(version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Wed, 20 Sep 2017 20:17:24 GMT","from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236])\n\tby userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id\n\tv8KKHNRL029802\n\t(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256\n\tverify=OK); Wed, 20 Sep 2017 20:17:24 GMT","from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14])\n\tby aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id\n\tv8KKHMfa028038; Wed, 20 Sep 2017 20:17:22 GMT","from xakep.us.oracle.com (/10.154.127.176)\n\tby default (Oracle Beehive Gateway v4.0)\n\twith ESMTP ; Wed, 20 Sep 2017 13:17:22 -0700"],"Authentication-Results":"ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=oracle.com\n\t(client-ip=156.151.31.81; helo=userp1040.oracle.com;\n\tenvelope-from=pasha.tatashin@oracle.com; receiver=)","From":"Pavel Tatashin ","To":"linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,\n\tlinux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,\n\tlinux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org,\n\tx86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com,\n\theiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, \n\tmhocko@kernel.org, ard.biesheuvel@linaro.org, mark.rutland@arm.com,\n\twill.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org,\n\tmgorman@techsingularity.net, steven.sistare@oracle.com,\n\tdaniel.m.jordan@oracle.com, bob.picco@oracle.com","Subject":"[PATCH v9 02/12] sparc64/mm: setting fields in deferred pages","Date":"Wed, 20 Sep 2017 16:17:04 -0400","Message-Id":"<20170920201714.19817-3-pasha.tatashin@oracle.com>","X-Mailer":"git-send-email 2.14.1","In-Reply-To":"<20170920201714.19817-1-pasha.tatashin@oracle.com>","References":"<20170920201714.19817-1-pasha.tatashin@oracle.com>","X-Source-IP":"userv0022.oracle.com [156.151.31.74]","X-BeenThere":"linuxppc-dev@lists.ozlabs.org","X-Mailman-Version":"2.1.24","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"},"content":"Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),\nflags and other fields in \"struct page\"es are never changed prior to first\ninitializing struct pages by going through __init_single_page().\n\nWith deferred struct page feature enabled there is a case where we set some\nfields prior to initializing:\n\nmem_init() {\n register_page_bootmem_info();\n free_all_bootmem();\n ...\n}\n\nWhen register_page_bootmem_info() is called only non-deferred struct pages\nare initialized. But, this function goes through some reserved pages which\nmight be part of the deferred, and thus are not yet initialized.\n\nmem_init\nregister_page_bootmem_info\nregister_page_bootmem_info_node\n get_page_bootmem\n .. setting fields here ..\n such as: page->freelist = (void *)type;\n\nfree_all_bootmem()\nfree_low_memory_core_early()\n for_each_reserved_mem_region()\n reserve_bootmem_region()\n init_reserved_page() <- Only if this is deferred reserved page\n __init_single_pfn()\n __init_single_page()\n memset(0) <-- Loose the set fields here\n\nWe end-up with similar issue as in the previous patch, where currently we\ndo not observe problem as memory is zeroed. But, if flag asserts are\nchanged we can start hitting issues.\n\nAlso, because in this patch series we will stop zeroing struct page memory\nduring allocation, we must make sure that struct pages are properly\ninitialized prior to using them.\n\nThe deferred-reserved pages are initialized in free_all_bootmem().\nTherefore, the fix is to switch the above calls.\n\nSigned-off-by: Pavel Tatashin \nReviewed-by: Steven Sistare \nReviewed-by: Daniel Jordan \nReviewed-by: Bob Picco \nAcked-by: David S. Miller \n---\n arch/sparc/mm/init_64.c | 8 +++++++-\n 1 file changed, 7 insertions(+), 1 deletion(-)","diff":"diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c\nindex 6034569e2c0d..310c6754bcaa 100644\n--- a/arch/sparc/mm/init_64.c\n+++ b/arch/sparc/mm/init_64.c\n@@ -2548,9 +2548,15 @@ void __init mem_init(void)\n {\n \thigh_memory = __va(last_valid_pfn << PAGE_SHIFT);\n \n-\tregister_page_bootmem_info();\n \tfree_all_bootmem();\n \n+\t/* Must be done after boot memory is put on freelist, because here we\n+\t * might set fields in deferred struct pages that have not yet been\n+\t * initialized, and free_all_bootmem() initializes all the reserved\n+\t * deferred pages for us.\n+\t */\n+\tregister_page_bootmem_info();\n+\n \t/*\n \t * Set up the zero page, mark it reserved, so that page count\n \t * is not manipulated when freeing the page from user ptes.\n","prefixes":["v9","02/12"]}