LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Chris Wilson <chris@chris-wilson.co.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Bandan Das <bsd@redhat.com>
Subject: Re: Linux 5.3-rc7
Date: Sat, 07 Sep 2019 16:24:48 +0100
Message-ID: <156786988815.13300.14460569616117208043@skylake-alporthouse-com> (raw)
In-Reply-To: <alpine.DEB.2.21.1909071657430.1902@nanos.tec.linutronix.de>

Quoting Thomas Gleixner (2019-09-07 16:00:17)
> Does this only happen with that CPU0 hotplug stuff enabled or on CPUs other
> than CPU0 as well? That hotplug CPU0 stuff is a bandaid so I wouldn't be
> surprised if we broke that somehow.

If I ignore cpu0 in that test and so use

[  133.847187] smpboot: CPU 1 is now offline
[  134.861861] x86: Booting SMP configuration:
[  134.861875] smpboot: Booting Node 0 Processor 1 APIC 0x2
[  134.880218] smpboot: CPU 2 is now offline
[  135.893806] smpboot: Booting Node 0 Processor 2 APIC 0x1
[  135.935115] smpboot: CPU 3 is now offline
[  136.949760] smpboot: Booting Node 0 Processor 3 APIC 0x3

that has run for 10 minutes without failure, so it seems confined to
cpu0 hotplugging. All we are doing in the test to generate the hotplugs
is:

for (int cpu = 0;; cpu++) {
	char name[128];
	int cpufd;

	snprintf(name, sizeof(name),
		 "/sys/devices/system/cpu/cpu%d/online",
		 cpu), sizeof(name));
	cpufd = open(name, O_WRONLY);
	if (cpufd < 0)
		break;

	write(cpufd, "0", 2);
	usleep(1e6);
	write(cpufd, "1", 2);

	close(cpufd);
}

-Chris

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-02 17:28 Linus Torvalds
2019-09-07 10:10 ` Chris Wilson
2019-09-07 14:29   ` Thomas Gleixner
2019-09-07 14:41     ` Chris Wilson
2019-09-07 15:00       ` Thomas Gleixner
2019-09-07 15:24         ` Chris Wilson [this message]
2019-09-07 20:12           ` Thomas Gleixner
2019-09-07 19:17         ` Linus Torvalds
2019-09-07 19:27           ` Linus Torvalds
2019-09-09 13:54             ` Bandan Das
2019-09-07 20:44           ` Thomas Gleixner
2019-09-07 21:13             ` Linus Torvalds
2019-09-08 11:02               ` Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=156786988815.13300.14460569616117208043@skylake-alporthouse-com \
    --to=chris@chris-wilson.co.uk \
    --cc=bsd@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git