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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 90750C10F14 for ; Thu, 18 Apr 2019 10:40:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D4562083D for ; Thu, 18 Apr 2019 10:40:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D4562083D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1B6BB6B0010; Thu, 18 Apr 2019 06:40:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 164576B0266; Thu, 18 Apr 2019 06:40:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 005EC6B0269; Thu, 18 Apr 2019 06:40:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) by kanga.kvack.org (Postfix) with ESMTP id 89E3D6B0010 for ; Thu, 18 Apr 2019 06:40:03 -0400 (EDT) Received: by mail-lj1-f197.google.com with SMTP id v20so347932ljk.7 for ; Thu, 18 Apr 2019 03:40:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:to:cc :references:from:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=wAlg1KOiSqebwGJaG9t1DzfCFJrSdBxkcX0xApPz9Zc=; b=XpcAraT9r0fEB1jUP3TR6VcpLmbfd6ptmy76GLUIkvEnlnFgj+PN0vM04OoakXVR8M qkRY/tkjNUrQK+5Pm68CP63AGJwgtzrNTA3K2N79u1yy2BToGrUL5vEbyl2qrJ/V5mOy karf8ZMq47SIX5Qqr5h8ga+EsT8XJaNoNUeFyFF6gbMhIzCDjkCMv1dyTf1lCIAVMu2K STd4L7tfyJz2uJoQT1C/YUm++9NoZsDenp5tNUlr7Q/MoTwqktwndPJw3tKPQW3VVlEq 4FCmIVhwRmoIfYCz0pBCW8r+oUTs1Y/tO6ie07VH90Wt79TLVI+jBCErzTJd6bflcMx6 Ja6g== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of aryabinin@virtuozzo.com designates 185.231.240.75 as permitted sender) smtp.mailfrom=aryabinin@virtuozzo.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=virtuozzo.com X-Gm-Message-State: APjAAAXyQ/8rrA1Ms4BsDPMa1B+4V1GI333NtTuFuckanjqsAz6gahKH j5S3msHzemvrRqoQ0A4VkgrmDoA7vBzhRth/bLdhS3EM6vAAKIpZn+fg/Lk4Y1bstIubQFs1uAc Y1P5svCDGxHc3JSVxkVtJgN6Ry89b9XZ2pylgpM2jLC8uIfVoVfkG14VRVyFu3oyrVQ== X-Received: by 2002:a19:e30b:: with SMTP id a11mr40113717lfh.4.1555584002853; Thu, 18 Apr 2019 03:40:02 -0700 (PDT) X-Google-Smtp-Source: APXvYqy+oNjVoyY4++SIy2BVutajGenQ7Y5f7JO138N5jjUedz4Z89i1xUgilVv0QbSPfT0Bp9s4 X-Received: by 2002:a19:e30b:: with SMTP id a11mr40113650lfh.4.1555584001567; Thu, 18 Apr 2019 03:40:01 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1555584001; cv=none; d=google.com; s=arc-20160816; b=cFrr/AwNklRSAaXVHnpL2Ergmqa+LcjtPhedrPE7hd9fqms9T+IDBtUEPJJmtaKAHX FGcN4KYfS1E+3WZpBi7Xxtmh9m/1Naoiu8ethY7hXoP7pWA59pkEA0BA1SnlnK7jyMTE m3WSAYK6HT0RN+XJu8rwwPEkyLXkFX7qsYDlIz6Cvk9TZmZPuQyEoHMiz4F4Zw5NtwtB uWSS9tj8WPtswLPkmJaa73kykq4OrN2UaDRPyOFSYg5xrUcj3wu4Da3rqSU21YQR3say /y46DV5kxkBpxiFx5f5FN+mncL9xbVuA09WevEkUEfRRBEGrnIyQgwSeaL7HkrASoH8X AVqA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject; bh=wAlg1KOiSqebwGJaG9t1DzfCFJrSdBxkcX0xApPz9Zc=; b=Z/Rxwohf5YMjhDQ/LioAEvfdKwIVTqhsorMgEl9cgGF/d6hsgHOTccQFj0Bdbnnf8+ cAa+Ha3Tm0FlOGhR2C+qNm0inuH2UbLmLOYKo2zdfh7RiNNbL65fEBPFTETJn/O/PQuD LchNCndr7Lc4KqMw+KWJ6SnABBCdZN+v7a4g37wDH/uwlgeU9zNTk6O9GgoEJ1hvjRBT nWGGTy94EJ+qPav6VBqz4J1KC3vqZqJpYK0Jr7ygOrRxYA+t9A1KzeVQut24W5VUgimm nrIj+3i4Kjlz82MvnMNV/UruZFh93B01PTKQsYPlaw+yuKgScsCu12lptzDCMjCA5fq0 yiwQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of aryabinin@virtuozzo.com designates 185.231.240.75 as permitted sender) smtp.mailfrom=aryabinin@virtuozzo.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=virtuozzo.com Received: from relay.sw.ru (relay.sw.ru. [185.231.240.75]) by mx.google.com with ESMTPS id k21si1358345ljj.204.2019.04.18.03.40.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 Apr 2019 03:40:01 -0700 (PDT) Received-SPF: pass (google.com: domain of aryabinin@virtuozzo.com designates 185.231.240.75 as permitted sender) client-ip=185.231.240.75; Authentication-Results: mx.google.com; spf=pass (google.com: domain of aryabinin@virtuozzo.com designates 185.231.240.75 as permitted sender) smtp.mailfrom=aryabinin@virtuozzo.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=virtuozzo.com Received: from [172.16.25.12] by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1hH4Rp-0002dq-HX; Thu, 18 Apr 2019 13:39:17 +0300 Subject: Re: [patch V2 09/29] mm/kasan: Simplify stacktrace handling To: Thomas Gleixner , LKML Cc: Josh Poimboeuf , x86@kernel.org, Andy Lutomirski , Steven Rostedt , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, Alexey Dobriyan , Andrew Morton , Pekka Enberg , David Rientjes , Christoph Lameter , Catalin Marinas , Mike Rapoport , Akinobu Mita , iommu@lists.linux-foundation.org, Robin Murphy , Christoph Hellwig , Marek Szyprowski , Johannes Thumshirn , David Sterba , Chris Mason , Josef Bacik , linux-btrfs@vger.kernel.org, dm-devel@redhat.com, Mike Snitzer , Alasdair Kergon , intel-gfx@lists.freedesktop.org, Joonas Lahtinen , Maarten Lankhorst , dri-devel@lists.freedesktop.org, David Airlie , Jani Nikula , Daniel Vetter , Rodrigo Vivi , linux-arch@vger.kernel.org References: <20190418084119.056416939@linutronix.de> <20190418084253.903603121@linutronix.de> From: Andrey Ryabinin Message-ID: <5b77992a-52b6-807e-f77d-9cf3e648c71f@virtuozzo.com> Date: Thu, 18 Apr 2019 13:39:45 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190418084253.903603121@linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 4/18/19 11:41 AM, Thomas Gleixner wrote: > Replace the indirection through struct stack_trace by using the storage > array based interfaces. > > Signed-off-by: Thomas Gleixner > Acked-by: Dmitry Vyukov > Cc: Andrey Ryabinin > Cc: Alexander Potapenko > Cc: kasan-dev@googlegroups.com > Cc: linux-mm@kvack.org Acked-by: Andrey Ryabinin > > static inline depot_stack_handle_t save_stack(gfp_t flags) > { > unsigned long entries[KASAN_STACK_DEPTH]; > - struct stack_trace trace = { > - .nr_entries = 0, > - .entries = entries, > - .max_entries = KASAN_STACK_DEPTH, > - .skip = 0 > - }; > + unsigned int nr_entries; > > - save_stack_trace(&trace); > - filter_irq_stacks(&trace); > - > - return depot_save_stack(&trace, flags); > + nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); > + nr_entries = filter_irq_stacks(entries, nr_entries); > + return stack_depot_save(entries, nr_entries, flags); Suggestion for further improvement: stack_trace_save() shouldn't unwind beyond irq entry point so we wouldn't need filter_irq_stacks(). Probably all call sites doesn't care about random stack above irq entry point, so it doesn't make sense to spend resources on unwinding non-irq stack from interrupt first an filtering out it later. It would improve performance of stack_trace_save() called from interrupt and fix page_owner which feed unfiltered stack to stack_depot_save(). Random non-irq part kills the benefit of using the stack_deopt_save().