From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_GMAIL_RCVD, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=no autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 73A621F466 for ; Tue, 14 Jan 2020 04:57:47 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; q=dns; s=default; b=aOxB LC0Act6+LAg7iW1BBJnpKWDHAmlRmhmBAYd0W40+AGY28eOeij+e2Nh0fN6ui5ku pwj6sJk2HO3UPEiuVHCnLMdZD+Twe4jJSg1fCWCiEgPSEvBmZCByHVlF2vErInnJ eiY9lpkN1oG2XrTUtbtLBeEIZIvTl2mqTaAG0ws= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; s=default; bh=MmwNwOb03Z //eaULzeYUXULcZrg=; b=CewgtduQRVW4MZS3ZRe/X4Ph5IpviM3ryeon/6Hk/O vP5dc80QsB6r0c/m45ojfs+ph2X6DHoCyy2TIfHC1i/Fo+WReydlV+xwvMh/d2n3 i8kIy7roT5QEEIQC4lchOqydl4rg3gbHHpejBz0WfVelzyXdrkgrdSwCeGuzw3J+ o= Received: (qmail 109053 invoked by alias); 14 Jan 2020 04:57:44 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 109045 invoked by uid 89); 14 Jan 2020 04:57:44 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-lf1-f49.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=16MYDCKYRo4GqRmK0xuLX0ETMjYhJ88tD47iFboJOyo=; b=bWM2ga8BVF2pd0fKXhugAzZS+wcKv70G1tpq20t/uz6FoYmzkDpMiECtdnYmaY+R1J LgjuAlMRxndJ/wAG5MGPwGAX1yJWFq4VL3RMtJewQhcATG3yRu/iX4/3ZbDvRactLoSS UevUjXTFoZG4SOCMUIa7Y4fHhp+9/PYo8dwKhQelHs2m5DoFkSXmkGOxu0HpUcV14Yai DRbeAvi5214BQx6/MiiPxFLqfvaqoz2HWpPyiWzRhYnkx22LWuGizTyCcyFD4tMuUflm 00vhK2Kosn0ztluqXRJ6WO4NbbjbN0IcBBQBbZiraaxvqbJD5IYV3l2snOcYm2cUrX34 ekmw== MIME-Version: 1.0 References: <20200114022856.GA24302@google.com> In-Reply-To: <20200114022856.GA24302@google.com> From: Alistair Francis Date: Tue, 14 Jan 2020 14:57:14 +1000 Message-ID: Subject: Re: Math errors To: Jonathan Nieder Cc: Jim Wilson , Joseph Myers , GNU C Library Content-Type: text/plain; charset="UTF-8" On Tue, Jan 14, 2020 at 12:28 PM Jonathan Nieder wrote: > > Hi, > > Alistair Francis wrote: > > On Wed, Jan 8, 2020 at 4:29 AM Jim Wilson wrote: > >> On Mon, Jan 6, 2020 at 5:33 PM Alistair Francis wrote: > > >>> I have the latest 5.4.x kernel, I'm not sure if that has it or not. > >> > >> I don't know. I don't follow linux kernel development that closely. > >> But the failures I sometimes see are test-fenv and test-fpucw which I > >> don't see in your list. > >> > >> I only run glibc testsuite on hardware though, and I've only been > >> testing rv64gc support. I haven't tried qemu. In the RISC-V software > >> meeting this morning, Palmer mentioned that there are some known > >> RISC-V qemu FP bugs, for instance fcmp doesn't set the FP reg dirty > >> bit when an exception flag is set, which could cause a testcase > >> failure if a context switch happens at the wrong time. This could > > > > I have noticed that running the tests not in parallel gives much better results > > Interesting. Can you provide full "uname -r" output? What Linux > distribution do you use? I don't have it in front of me right now, but it's 5.4.x and built from OpenEmbedded. > > I suspect the issue Jim mentioned is fixed by v5.3-rc5~12^2~1 ("riscv: > Correct the initialized flow of FP register", 2019-08-14), which you > would already have. That said, the 5.5-rc series has some more fp reg > handling fixes. It could be a QEMU issue: https://lists.gnu.org/archive/html/qemu-devel/2020-01/msg02455.html Alistair > > [...] > >> Someone will have to look at the rv32gc math failures, and keep an > >> open mind that they could be glibc, qemu, gcc, linux kernel, etc > > > > Yeah, that's what I was thinking. There are only a few math tests left > > failing, so it's not too bad. Thanks for the information Jim. > > That it appears more often with threading does suggest some kind of FP > register leakage. > > Thanks and happy hunting, > Jonathan