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=-8.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,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 D89EAC388F7 for ; Sat, 7 Nov 2020 14:09:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F9A420719 for ; Sat, 7 Nov 2020 14:09:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qwTiHcHF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728161AbgKGOJU (ORCPT ); Sat, 7 Nov 2020 09:09:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727608AbgKGOJT (ORCPT ); Sat, 7 Nov 2020 09:09:19 -0500 Received: from mail-qv1-xf33.google.com (mail-qv1-xf33.google.com [IPv6:2607:f8b0:4864:20::f33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D762C0613CF for ; Sat, 7 Nov 2020 06:09:19 -0800 (PST) Received: by mail-qv1-xf33.google.com with SMTP id ed14so1850788qvb.4 for ; Sat, 07 Nov 2020 06:09:19 -0800 (PST) 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=lYy5Q3j0/qHRIQpHmgQwRhPL3ZQjA9zi9iui5vgp2XM=; b=qwTiHcHFqwmH53Mhh5UOm1mKjP+otZw08ITadxSk/hsECmsTJAn1fDO0tAu49ETzJk NmrUVY13XOwZMONaPuC19V8xRP3qeX99MZyey+m47MODThRU+y78TdpOEY61UPwpVBxV v3Kx6UHczh7lmZIOZ+449czRObgbfT/PhSCS4vnvydVkxA3Xq8lVctqLimtPvJX0RgbP l5Asudnai4JmC5xj4h8SkplvOLuAjdgOmEQk4CdLHI4FcPLa+GY+FT4sPIRtSj9ZNjJe 4gmSHIZ+mW9p7GxKYvA2+sWZwX2aE6L19um6CH7NHDzWWJvw63ax4tCYle22UsB/enfz eg5w== 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=lYy5Q3j0/qHRIQpHmgQwRhPL3ZQjA9zi9iui5vgp2XM=; b=eoemt5LXgKzB1x9ZwRHwnpAmIY8aIOLzd9jPWtBkvW+3gAntrf6ySPfCdRQvUaKNAa miFtNGKTjg8hbUnyu6nLF1x8mknE5KVtVJ3Tgn6/5kvKIHJVxnEPZ/oiRJuOJn9Tqm6d Wrq+XJ3qGwgxB4mwDAeB3gU0xkG18ONQCvM6PboOcD56VdNdKOQgNl+Ob3ZJoz4/kWgt TmnqvZ8aqkCU5poqnjVUcjkPA4UxF5Nygm6p1+fcOt6B7z/rG+bid7MkE/dtv7eQxHQB lcK2ymKHsjhKupGZY2p3BDo24QNiCxCH1qFpPdynEvfcBiSr/l2cg8xFO27jVxiCwvny fUqw== X-Gm-Message-State: AOAM533e+YdFTi8mZ30FdPsERQDdc6c3xkAxE+eA6rODDCz++HXp0Gj3 A7wRo7279fdXmG3lBjB+IeJPLqzQ4mq2TZC5brg= X-Google-Smtp-Source: ABdhPJw3Ch9Ju0ovIX6cYrijkZ4KG5wapmCE//TeePjecrc6lfRKnGzXEsLhcmzHcXmrFB63U0rAg+Ju7slRxKNS0As= X-Received: by 2002:ad4:5381:: with SMTP id i1mr6262924qvv.21.1604758158633; Sat, 07 Nov 2020 06:09:18 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Josef Date: Sat, 7 Nov 2020 15:09:07 +0100 Message-ID: Subject: Re: Using SQPOLL for-5.11/io_uring kernel NULL pointer dereference To: Pavel Begunkov , io-uring , Jens Axboe Cc: norman@apache.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org > I haven't got the first email, is it "kernel NULL pointer dereference" > as in the subject or just freeze? that's weird..probably the size of the attached log file is too big... here dmesg log file https://gist.github.com/1Jo1/3d0bcefc18f097265f0dc1ef054a87c0 > - did you locate which test hangs it? If so what it uses? e.g. SQPOLL > sharing, IOPOLL., etc. yes, it uses SQPOLL, without sharing, IPOLL is not enabled, and Async Flag is enabled > - is it send/recvmsg, send/recv you use? any other? no the tests which occurs the error use these operations: OP_READ, OP_WRITE, OP_POLL_ADD, OP_POLL_REMOVE, OP_CLOSE, OP_ACCEPT, OP_TIMEOUT (OP_READ, OP_WRITE and OP_CLOSE async flag is enabled) > - does this happen often? yeah quite often > - you may try `funcgraph __io_sq_thread -H` or even with `io_sq_thread` > (funcgraph is from bpftools). Or catch that with some other tools. I'm not quite familiar with these tools( kernel debugging in general) I'll take a look tomorrow ernel NULL pointer dereference" > as in the subject or just freeze? > > also > - anything in dmesg? (>5 min after freeze) > - did you locate which test hangs it? If so what it uses? e.g. SQPOLL > sharing, IOPOLL., etc. > - is it send/recvmsg, send/recv you use? any other? > - does this happen often? > - you may try `funcgraph __io_sq_thread -H` or even with `io_sq_thread` > (funcgraph is from bpftools). Or catch that with some other tools. > > -- > Pavel Begunkov