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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29E09C433F5 for ; Thu, 21 Apr 2022 16:32:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230520AbiDUQfD (ORCPT ); Thu, 21 Apr 2022 12:35:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231653AbiDUQer (ORCPT ); Thu, 21 Apr 2022 12:34:47 -0400 Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com [IPv6:2a00:1450:4864:20::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6ABC496A1 for ; Thu, 21 Apr 2022 09:31:22 -0700 (PDT) Received: by mail-lj1-x231.google.com with SMTP id bf11so6430868ljb.7 for ; Thu, 21 Apr 2022 09:31:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=FDHwtTdktvnVaIW/2JWrDjqUVZR9rEX/QovVhwcUaVw=; b=e6Q+A3Cw3J49kCJ+zuxnLYRX59f2aqNTPi2FdOE+44LcRv2+/Tqms9+royj30R+qv/ 63foTaGKolV/B5vsrdf60lb4GSXIYbkMeCbebG+BNfRQhUzdwp519h0mbz2f64vTXqFz juJRK/yjfkTO3d+BGRR8pOmGa0TnE6PJDsDrs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=FDHwtTdktvnVaIW/2JWrDjqUVZR9rEX/QovVhwcUaVw=; b=5aETt+BkHKkl/s7cWMz/c127ojHFsZn0+yc53B+C/KkQtLIqg0YFV3gPB3eYp7KyFJ wphC2kE2iNoUCQpbgxgteoSfB3a7oT6uC84zxVjzsdGNaqYjUl3yMb+ZHVayGhNVRH8b 9LexaMIyqF9MrVzStKT776LK5yXJkR4rcVzkm/nQTZMQxsJKK9UqzVCTAAMDUk3zHVrl pVRWcJaCyZ0b93OeAFvr5/I81QvsE061ca8Izx/cTb+uxoNWkiSQ8q3zMdMTpPyCDQJ3 5Q45+Ix2X3m9TR7+T3qakP4Ha9Xbjo7HLN8zm/mzG3Qmy9DwjDzVOgLm0NsdPdhc4DjT A0OQ== X-Gm-Message-State: AOAM531Z44He6qS06kBRKTvA2/bQZx99CG8S49mDMJQiQAN71Iz5u+Lv 6i0Gm1jY+PaBvcG+VxGA5zbkcPxEBAJ3jTFXcVE= X-Google-Smtp-Source: ABdhPJz5lUUlZmS1yxuVZNFobbnjiHgF4N3PpPIH2nxHb1VfNP9d6RYqBQz/lICgTMv2/nog8X3F3g== X-Received: by 2002:a05:651c:1791:b0:24b:1797:53b1 with SMTP id bn17-20020a05651c179100b0024b179753b1mr306237ljb.269.1650558680905; Thu, 21 Apr 2022 09:31:20 -0700 (PDT) Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com. [209.85.208.178]) by smtp.gmail.com with ESMTPSA id z1-20020a195041000000b0046d191d1e91sm2222433lfj.169.2022.04.21.09.31.16 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Apr 2022 09:31:16 -0700 (PDT) Received: by mail-lj1-f178.google.com with SMTP id v1so3037656ljv.3 for ; Thu, 21 Apr 2022 09:31:16 -0700 (PDT) X-Received: by 2002:a2e:b818:0:b0:24c:ce86:e6d6 with SMTP id u24-20020a2eb818000000b0024cce86e6d6mr297100ljo.443.1650558675957; Thu, 21 Apr 2022 09:31:15 -0700 (PDT) MIME-Version: 1.0 References: <20220420073717.GD16310@xsang-OptiPlex-9020> In-Reply-To: From: Linus Torvalds Date: Thu, 21 Apr 2022 09:30:59 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [fs/pipe] 5a519c8fe4: WARNING:at_mm/page_alloc.c:#__alloc_pages To: Andrei Vagin Cc: kernel test robot , Dmitry Safonov <0x7f454c46@gmail.com>, Alexander Viro , Andrew Morton , LKML , lkp@lists.01.org, kernel test robot , Mike Rapoport Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 21, 2022 at 8:35 AM Andrei Vagin wrote: > > The operation of injecting/curing parasite code from the > process is expensive and requires freezing a process. This is why we > want to maximize the load that we can carry on for each iteration. Honestly, it sounds like what you want is just process_vm_readv(). The pipe part sounds like a horrible hacky thing. I also assume you already tried that, and hit some performance issues. But it does sound like the better interface, more directly what you want. So what are the problems with using process_vm_readv? Linus