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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33AB6C433F5 for ; Fri, 12 Nov 2021 12:31:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C12A60E73 for ; Fri, 12 Nov 2021 12:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235093AbhKLMeN (ORCPT ); Fri, 12 Nov 2021 07:34:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53097 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234986AbhKLMdy (ORCPT ); Fri, 12 Nov 2021 07:33:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636720264; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=ycYx9/XAV/t6C65tgZcqevoi8s8QF2jfiLtobYL9K+o=; b=EDFpvrnxhJLx8Uhu+JTzWP9tda4YM2ordEI6eFEf7za6L5Jg9IR+JiI4ckiyIWIyFtE/D6 X/7wzikXi1Na3XVJDW67dQ2SOpxrc124zpio9i04fwdlN9YERlQKWToLie3DffdcdQAzw8 oPzfbOzIQ6boBOKwJNlRfYlIH+6w1rk= 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-393-YqsTs97rNDyTQFl0ivjxEA-1; Fri, 12 Nov 2021 07:31:01 -0500 X-MC-Unique: YqsTs97rNDyTQFl0ivjxEA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 34226106D8EF; Fri, 12 Nov 2021 12:30:30 +0000 (UTC) Received: from fuller.cnet (ovpn-112-6.gru2.redhat.com [10.97.112.6]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E1E771053B39; Fri, 12 Nov 2021 12:30:29 +0000 (UTC) Received: by fuller.cnet (Postfix, from userid 1000) id 821E440C5C1D; Fri, 12 Nov 2021 09:29:05 -0300 (-03) Message-ID: <20211112122641.543982929@fedora.localdomain> User-Agent: quilt/0.66 Date: Fri, 12 Nov 2021 09:16:46 -0300 From: Marcelo Tosatti To: linux-kernel@vger.kernel.org Cc: Nitesh Lal , Nicolas Saenz Julienne , Frederic Weisbecker , Christoph Lameter , Juri Lelli , Peter Zijlstra , Alex Belits , Peter Xu , Thomas Gleixner , Daniel Bristot de Oliveira Subject: [patch v6 04/10] procfs: add per-pid task isolation state X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The logic to disable vmstat worker thread, when entering nohz full, does not cover all scenarios. For example, it is possible for the following to happen: References: <20211112121642.693790927@fedora.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Add /proc/pid/task_isolation file, to query the state of task isolation configuration. --- fs/proc/base.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) Index: linux-2.6/fs/proc/base.c =================================================================== --- linux-2.6.orig/fs/proc/base.c +++ linux-2.6/fs/proc/base.c @@ -96,6 +96,8 @@ #include #include #include +#include +#include #include #include "internal.h" #include "fd.h" @@ -662,6 +664,69 @@ static int proc_pid_syscall(struct seq_f } #endif /* CONFIG_HAVE_ARCH_TRACEHOOK */ +#ifdef CONFIG_CPU_ISOLATION + +struct qoptions { + unsigned long mask; + char *name; +}; + +static struct qoptions iopts[] = { + {ISOL_F_QUIESCE, "quiesce"}, +}; +#define ILEN (sizeof(iopts) / sizeof(struct qoptions)) + +static struct qoptions qopts[] = { + {ISOL_F_QUIESCE_VMSTATS, "vmstat_sync"}, +}; +#define QLEN (sizeof(qopts) / sizeof(struct qoptions)) + +static void show_isolation_state(struct seq_file *m, + struct qoptions *iopt, + int mask, + const char *hdr) +{ + int i; + + seq_printf(m, hdr); + for (i = 0; i < ILEN; i++) { + if (mask & iopt->mask) + seq_printf(m, "%s ", iopt->name); + iopt++; + } + if (mask == 0) + seq_printf(m, "none "); + seq_printf(m, "\n"); +} + +int proc_pid_task_isolation(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *t) +{ + int active_mask, quiesce_mask, conf_mask; + struct isol_info *isol_info; + struct inode *inode = m->private; + struct task_struct *task = get_proc_task(inode); + + isol_info = t->isol_info; + if (!isol_info) + active_mask = quiesce_mask = conf_mask = 0; + else { + active_mask = isol_info->active_mask; + quiesce_mask = isol_info->quiesce_mask; + conf_mask = isol_info->conf_mask; + } + + show_isolation_state(m, iopts, conf_mask, "Configured state: "); + show_isolation_state(m, iopts, active_mask, "Active state: "); + show_isolation_state(m, qopts, quiesce_mask, "Quiescing: "); + + put_task_struct(task); + + return 0; +} + +#endif /* CONFIG_CPU_ISOLATION */ + /************************************************************************/ /* Here the fs part begins */ /************************************************************************/ @@ -3281,6 +3346,9 @@ static const struct pid_entry tgid_base_ #ifdef CONFIG_SECCOMP_CACHE_DEBUG ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache), #endif +#ifdef CONFIG_CPU_ISOLATION + ONE("task_isolation", S_IRUSR, proc_pid_task_isolation), +#endif }; static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)