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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no 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 97FCBC5519F for ; Thu, 12 Nov 2020 16:09:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1187C22240 for ; Thu, 12 Nov 2020 16:09:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Y0UBlSyA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1187C22240 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 362566B0074; Thu, 12 Nov 2020 11:09:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 33A226B0075; Thu, 12 Nov 2020 11:09:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 228606B0078; Thu, 12 Nov 2020 11:09:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0081.hostedemail.com [216.40.44.81]) by kanga.kvack.org (Postfix) with ESMTP id E8F5F6B0074 for ; Thu, 12 Nov 2020 11:09:33 -0500 (EST) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 8EC5A8249980 for ; Thu, 12 Nov 2020 16:09:33 +0000 (UTC) X-FDA: 77476251426.01.ants43_61132b527307 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin01.hostedemail.com (Postfix) with ESMTP id 6B4A41004646A for ; Thu, 12 Nov 2020 16:09:33 +0000 (UTC) X-HE-Tag: ants43_61132b527307 X-Filterd-Recvd-Size: 4148 Received: from mail-ot1-f67.google.com (mail-ot1-f67.google.com [209.85.210.67]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Nov 2020 16:09:32 +0000 (UTC) Received: by mail-ot1-f67.google.com with SMTP id f16so6052173otl.11 for ; Thu, 12 Nov 2020 08:09:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4E3aNnRy7r7yE8tRTHVuCw1bn/xlTevCdbx03WDIkcU=; b=Y0UBlSyAlEG5wAC+1573r6LeHcNPeOPXBJvlsLmyJl9ZrfDQ3IqdTddHz8R3N7UXoU qmLq5HDGLOKM4IEtPxvDrScYZGgaI+BKDjQJGGjm84TnLbeNgapSHEBTaRZNFCCp5Aap wAL+yrrJ6kFzhvo10NSUHrOLnToMOldT/NHE6XgIV4wDhwIC5FbB9LP4onOM93VBu/uQ bQG4F7wdsCRjFpXGl3Rd5hyVeYO07FKSpe2MlGq6IDMrVkezWHQ9sZCIjn4v8XrS2FkK h7PV5ujjZZoRCcxvQRe4IT3O2pgclMrD8/jHKDW/P7YqMFrA6HX9I+9C7KD3ANd6c0Tv 4B+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4E3aNnRy7r7yE8tRTHVuCw1bn/xlTevCdbx03WDIkcU=; b=hhLbsxiZwJjENzP3GbC0TWBtWWR1NYaBNcd4ZmxpRY34uhxxnEjqmiE/kya0RtbEw4 P/mNvD4kiKdzS4iOgWsDe0Yxe0gqfuSjfZqTpblDgo65VBkz6seGZhI1sXXllNSrXE7P lIqRGut8sPwHIzIejHHdCPPvJCQLxWPyQHQw9w2R6/dsnBQcnRWEgfhTe7BlEdQbysQ8 EeZAZJhMsjD8xhNAGCa5zLDIaMDeb9cXwbyqUI59Wq/wMiaVa5qmjyrEKEph3frezzue Fw1wR9ZiUpS+BBqpmLFs7bH77SE10PMZMT1/397s8N1pTFLf4qbcjqoOzW0AMO062DiL P3xw== X-Gm-Message-State: AOAM532n2xmi5r5wTJ9UAdcXTlHvCzbX9qchRNctWQJgO5uyca+xHj35 o9hAGlpDmE/sInd5KUjREefAKp6byhPrSIpiLhfW3w== X-Google-Smtp-Source: ABdhPJwwPDL+OOchIhN43aJaZdWLSzq3g/4c4+pX3LVmYRLcTq9IHuG5sWKShxGDdJOnfOCGmFfEjElZtmXGKjuL+vM= X-Received: by 2002:a9d:65d5:: with SMTP id z21mr20378820oth.251.1605197370706; Thu, 12 Nov 2020 08:09:30 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Thu, 12 Nov 2020 17:09:18 +0100 Message-ID: Subject: Re: [PATCH v9 44/44] kselftest/arm64: Check GCR_EL1 after context switch To: Alexander Potapenko Cc: Andrey Konovalov , Catalin Marinas , Will Deacon , Vincenzo Frascino , Dmitry Vyukov , Andrey Ryabinin , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , Andrew Morton , kasan-dev , Linux ARM , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" 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 Thu, 12 Nov 2020 at 16:59, Alexander Potapenko wrote: > > On Tue, Nov 10, 2020 at 11:12 PM Andrey Konovalov wrote: > > > > From: Vincenzo Frascino > > > > This test is specific to MTE and verifies that the GCR_EL1 register > > is context switched correctly. > > > > It spawn 1024 processes and each process spawns 5 threads. Each thread > > Nit: "spawns" > > > > + srand(time(NULL) ^ (pid << 16) ^ (tid << 16)); > > + > > + prctl_tag_mask = rand() % 0xffff; > > Nit: if you want values between 0 and 0xffff you probably want to use > bitwise AND. Another question would be, is the max here meant to be 0xffff or 0xffff-1. Because, as-is now, it's 0xffff-1. Only one of them has a trivial conversion to bitwise AND ( x % 2^n == x & (2^n - 1) ).