From: Borislav Petkov <bp@alien8.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
rt@linutronix.de, tglx@linutronix.de
Subject: Re: [PATCH 06/21] x86: microcode: Convert to hotplug state machine
Date: Wed, 7 Sep 2016 13:36:40 +0200 [thread overview]
Message-ID: <20160907113640.i27zhdoo3eszdlcw@pd.tnic> (raw)
In-Reply-To: <20160906170457.32393-7-bigeasy@linutronix.de>
On Tue, Sep 06, 2016 at 07:04:42PM +0200, Sebastian Andrzej Siewior wrote:
> Install the callbacks via the state machine. There is little hackery with
> mc_cpu_dead() which should only be called if CPU_UP failed durin resume.
> This change may not fully represent the current behaviour. The current code
> also behaves different if the CPU does not come up in the _cpu_up() state vs
> one of the CPU_ONLINE notifier returned an error. Not sure what kind of a
> problem is solved here.
You mean this:
/* The CPU refused to come up during a system resume */
if (action == CPU_UP_CANCELED_FROZEN)
microcode_fini_cpu(cpu);
?
It clears internal state, i.e., invalidates the current microcode patch.
>
> Cc: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
> arch/x86/kernel/cpu/microcode/core.c | 71 +++++++++++++++---------------------
> include/linux/cpuhotplug.h | 1 +
> 2 files changed, 30 insertions(+), 42 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
> index df04b2d033f6..4fc67b51e22e 100644
> --- a/arch/x86/kernel/cpu/microcode/core.c
> +++ b/arch/x86/kernel/cpu/microcode/core.c
...
> -static struct notifier_block mc_cpu_notifier = {
> - .notifier_call = mc_cpu_callback,
> -};
> +static int mc_cpu_down_prep(unsigned int cpu)
> +{
> + struct device *dev;
> +
> + dev = get_cpu_device(cpu);
> + /* Suspend is in progress, only remove the interface */
> + sysfs_remove_group(&dev->kobj, &mc_attr_group);
> + pr_debug("CPU%d removed\n", cpu);
> + return 0;
> +}
> +
> +static int mc_cpu_dead(unsigned int cpu)
> +{
> +#ifdef CONFIG_SMP
> + if (cpuhp_tasks_frozen)
> + microcode_fini_cpu(cpu);
> +#endif
> + return 0;
> +}
If this is corresponding to CPU_DEAD, then I'd like to point to that comment:
/*
* case CPU_DEAD:
*
* When a CPU goes offline, don't free up or invalidate the copy of
* the microcode in kernel memory, so that we can reuse it when the
* CPU comes back online without unnecessarily requesting the userspace
* for it again.
*/
IOW, you don't need mc_cpu_dead().
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
next prev parent reply other threads:[~2016-09-07 11:36 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-06 17:04 cpu hotplug: convert more drivers (batch #3) Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 01/21] arm64: FP/SIMD: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-09-06 18:14 ` Will Deacon
2016-09-19 19:51 ` [tip:smp/hotplug] arm64/FP/SIMD: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 02/21] ARM: shmobile: " Sebastian Andrzej Siewior
2016-09-06 18:05 ` Geert Uytterhoeven
2016-09-07 13:58 ` Sebastian Andrzej Siewior
2016-09-19 19:52 ` [tip:smp/hotplug] ARM/shmobile: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 03/21] ARM: OMAP: wakeupgen: " Sebastian Andrzej Siewior
2016-09-13 22:24 ` Tony Lindgren
2016-09-19 19:52 ` [tip:smp/hotplug] ARM/OMAP/wakeupgen: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 04/21] ia64: mca: " Sebastian Andrzej Siewior
2016-09-19 19:53 ` [tip:smp/hotplug] ia64/mca: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 05/21] sh: SH-X3 SMP: " Sebastian Andrzej Siewior
2016-09-19 19:53 ` [tip:smp/hotplug] sh/SH-X3 " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 06/21] x86: microcode: " Sebastian Andrzej Siewior
2016-09-07 11:36 ` Borislav Petkov [this message]
2016-09-07 14:51 ` Sebastian Andrzej Siewior
2016-09-07 16:02 ` Borislav Petkov
2016-09-07 16:45 ` [PATCH 06/21 v2] " Sebastian Andrzej Siewior
2016-09-19 19:54 ` [tip:smp/hotplug] x86/microcode: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 07/21] lib: irq_poll: " Sebastian Andrzej Siewior
2016-09-19 19:54 ` [tip:smp/hotplug] lib/irq_poll: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 08/21] block: softirq: " Sebastian Andrzej Siewior
2016-09-19 19:55 ` [tip:smp/hotplug] block/softirq: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 09/21] oprofile: timer: " Sebastian Andrzej Siewior
2016-09-19 19:55 ` [tip:smp/hotplug] oprofile/timer: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 10/21] virtio scsi: " Sebastian Andrzej Siewior
2016-09-19 19:56 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 11/21] ACPI: processor: " Sebastian Andrzej Siewior
2016-09-06 21:08 ` Rafael J. Wysocki
2016-09-07 14:01 ` Sebastian Andrzej Siewior
2016-09-07 15:59 ` Rafael J. Wysocki
2016-09-19 19:56 ` [tip:smp/hotplug] ACPI/processor: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 12/21] cpufreq: " Sebastian Andrzej Siewior
2016-09-06 21:27 ` Rafael J. Wysocki
2016-09-07 14:18 ` Sebastian Andrzej Siewior
2016-09-07 15:58 ` Rafael J. Wysocki
2016-09-19 19:56 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-09-20 14:56 ` [PATCH] cpufreq: fix up conversion " Sebastian Andrzej Siewior
2016-09-20 15:07 ` [tip:smp/hotplug] cpufreq: Fix " tip-bot for Sebastian Andrzej Siewior
2016-09-20 16:08 ` Borislav Petkov
2016-09-20 16:17 ` [PATCH] cpufreq: fix " Rafael J. Wysocki
2016-09-06 17:04 ` [PATCH 13/21] padata: Convert " Sebastian Andrzej Siewior
2016-09-19 19:57 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 14/21] fault-injection: cpu: " Sebastian Andrzej Siewior
2016-09-19 19:57 ` [tip:smp/hotplug] fault-injection/cpu: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 15/21] mips: octeon: smp: " Sebastian Andrzej Siewior
2016-09-07 8:24 ` Matt Redfearn
2016-09-07 14:27 ` Sebastian Andrzej Siewior
2016-09-08 8:34 ` Matt Redfearn
2016-09-19 15:10 ` Ralf Baechle
2016-09-19 19:58 ` [tip:smp/hotplug] mips/octeon/smp: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 16/21] mips: loongson: smp: " Sebastian Andrzej Siewior
2016-09-19 15:10 ` Ralf Baechle
2016-09-19 19:58 ` [tip:smp/hotplug] mips/loongson/smp: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 17/21] s390: mm: pfault: " Sebastian Andrzej Siewior
2016-09-19 19:59 ` [tip:smp/hotplug] s390/mm/pfault: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 18/21] x86: apic: uv: " Sebastian Andrzej Siewior
2016-09-19 19:59 ` [tip:smp/hotplug] x86/apic/uv: " tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 19/21] blk: mq: reserve hotplug ID states for block Sebastian Andrzej Siewior
2016-09-19 20:03 ` [tip:smp/hotplug] blk/mq: Reserve hotplug ID states for block multiqueue tip-bot for Sebastian Andrzej Siewior
2016-09-19 21:24 ` [tip:smp/hotplug] blk/mq: Reserve hotplug " tip-bot for Sebastian Andrzej Siewior
2016-09-21 7:45 ` tip-bot for Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 20/21] blk: mq: cpu-notif: Convert to hotplug state machine Sebastian Andrzej Siewior
2016-09-06 17:04 ` [PATCH 21/21] blk: mq: " Sebastian Andrzej Siewior
Reply instructions:
You may reply publicly 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=20160907113640.i27zhdoo3eszdlcw@pd.tnic \
--to=bp@alien8.de \
--cc=bigeasy@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rt@linutronix.de \
--cc=tglx@linutronix.de \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).