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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 3C2FEC43381 for ; Mon, 11 Mar 2019 07:28:32 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 A698120657 for ; Mon, 11 Mar 2019 07:28:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=yandex.com header.i=@yandex.com header.b="GtfQlVnR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A698120657 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yandex.com Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=kernelnewbies-bounces@kernelnewbies.org Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.91) (envelope-from ) id 1h3FLj-0003dt-U3; Mon, 11 Mar 2019 03:27:51 -0400 Received: from forward101p.mail.yandex.net ([77.88.28.101]) by shelob.surriel.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1h3FLj-0003dn-1z for kernelnewbies@kernelnewbies.org; Mon, 11 Mar 2019 03:27:51 -0400 Received: from mxback14o.mail.yandex.net (mxback14o.mail.yandex.net [IPv6:2a02:6b8:0:1a2d::65]) by forward101p.mail.yandex.net (Yandex) with ESMTP id 56CFE328184C; Mon, 11 Mar 2019 10:27:45 +0300 (MSK) Received: from localhost (localhost [::1]) by mxback14o.mail.yandex.net (nwsmtp/Yandex) with ESMTP id nl7Gn0zgAN-RitC932u; Mon, 11 Mar 2019 10:27:44 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.com; s=mail; t=1552289264; bh=UM40BqH9vpRyPECnbmqJSO8OUrgZIxAEseVnGACL05M=; h=Message-Id:Date:Subject:To:From; b=GtfQlVnR5dGCw3XsLmN1/m+n/qtq0Lvrn9r+vIMo4C9SGRuSyA2ljlj8UcaCd/kEg ByGcc4PTMf1nQ5D2cCCLrX6gXRvPsMWA/lUMHb4TLS+d5u3Q+LNSIHM/MYfEy+mhfs 4JdZk9/9hyUgVIYWht5gaBGEHDjAv3fd9bC8gifw= Authentication-Results: mxback14o.mail.yandex.net; dkim=pass header.i=@yandex.com Received: by iva7-7c2970ec7645.qloud-c.yandex.net with HTTP; Mon, 11 Mar 2019 10:27:44 +0300 From: Lev Olshvang To: kernelnewbies , linux-il Subject: What will happen on attempt to write to read-only page when CONFIG_MEM_SOFT_DIRTY is off ? MIME-Version: 1.0 X-Mailer: Yamail [ http://yandex.ru ] 5.0 Date: Mon, 11 Mar 2019 10:27:44 +0300 Message-Id: <21618991552289264@iva7-7c2970ec7645.qloud-c.yandex.net> X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org Hello all, Please help me to clarify what will page fault handler do (if any) File arch/x86/include/asm/pgtable_types.h have following comment for 2 PAGE_DIRTY_BITs #define _PAGE_BIT_DIRTY 6 /* was written to (raised by CPU) */ _PAGE_BIT_SOFT_DIRTY _PAGE_BIT_SOFTW3 /* software dirty tracking */ While documentation clearly explains that Page Fault handler sets second flag https://www.kernel.org/doc/Documentation/vm/soft-dirty.txt I do not have idea what will happen when tracking Soft Dirty flags is off, I suppose the answer is in mm/gup.c but I was not able to track it to page handler. Thanks you all. Lev. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies