From patchwork Tue Jun 16 16:11:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 213136 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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS 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 04B8DC433E1 for ; Tue, 16 Jun 2020 16:15:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D647C20882 for ; Tue, 16 Jun 2020 16:15:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JmwrWt5j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732342AbgFPQPW (ORCPT ); Tue, 16 Jun 2020 12:15:22 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:24840 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731921AbgFPQPU (ORCPT ); Tue, 16 Jun 2020 12:15:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592324119; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=Sc4OR5A24njzBYo2XyZ6e1pErQVd9vzc9p6oV8BP3Ms=; b=JmwrWt5j3NUWU6Ws/+ZgZWGx8JuskC8Ibyae28MAi0A9kJGGIYA8J/agar6tf/rf06uZrK 1L9eE5p1NLqxvOvoYiS2aX5oeV9Xw2AOCGvOryOPgf2OxwKuFfXGnCZp+6m7hGGmAkfEfF vyOCpteVPhnHl4IvU7tpwCIiiaClvKI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-355-xmAOxgy-P9W6UOk_u-DFjA-1; Tue, 16 Jun 2020 12:15:16 -0400 X-MC-Unique: xmAOxgy-P9W6UOk_u-DFjA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C6CF88005AD; Tue, 16 Jun 2020 16:15:15 +0000 (UTC) Received: from fuller.cnet (ovpn-112-9.gru2.redhat.com [10.97.112.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD6296ED96; Tue, 16 Jun 2020 16:15:12 +0000 (UTC) Received: by fuller.cnet (Postfix, from userid 1000) id B463541887FC; Tue, 16 Jun 2020 13:14:49 -0300 (-03) Message-ID: <20200616161149.392213902@fuller.cnet> User-Agent: quilt/0.66 Date: Tue, 16 Jun 2020 13:11:49 -0300 From: Marcelo Tosatti To: linux-rt-users@vger.kernel.org Cc: Sebastian Andrzej Siewior , Juri Lelli , Thomas Gleixner Subject: [patch 0/2] re-enable remote per-cpu-pages draining X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Remote draining of pages was removed from 5.6-rt. Unfortunately its necessary for use-cases which have a busy spinning SCHED_FIFO thread on isolated CPU: [ 7475.821066] INFO: task ld:274531 blocked for more than 600 seconds. [ 7475.822157] Not tainted 4.18.0-208.rt5.20.el8.x86_64 #1 [ 7475.823094] echo 0 /proc/sys/kernel/hung_task_timeout_secs disables this message. [ 7475.824392] ld D 0 274531 274530 0x00084080 [ 7475.825307] Call Trace: [ 7475.825761] __schedule+0x342/0x850 [ 7475.826377] schedule+0x39/0xd0 [ 7475.826923] schedule_timeout+0x20e/0x410 [ 7475.827610] ? __schedule+0x34a/0x850 [ 7475.828247] ? ___preempt_schedule+0x16/0x18 [ 7475.828953] wait_for_completion+0x85/0xe0 [ 7475.829653] flush_work+0x11a/0x1c0 [ 7475.830313] ? flush_workqueue_prep_pwqs+0x130/0x130 [ 7475.831148] drain_all_pages+0x140/0x190 [ 7475.831803] __alloc_pages_slowpath+0x3f8/0xe20 [ 7475.832571] ? mem_cgroup_commit_charge+0xcb/0x510 [ 7475.833371] __alloc_pages_nodemask+0x1ca/0x2b0 [ 7475.834134] pagecache_get_page+0xb5/0x2d0 [ 7475.834814] ? account_page_dirtied+0x11a/0x220 [ 7475.835579] grab_cache_page_write_begin+0x1f/0x40 [ 7475.836379] iomap_write_begin.constprop.44+0x1c1/0x370 [ 7475.837241] ? iomap_write_end+0x91/0x290 [ 7475.837911] iomap_write_actor+0x92/0x170 See individual patches for details.