public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman•id.au>
To: Nicholas Piggin <npiggin@gmail•com>,
	Gautham R Shenoy <ego@linux•vnet.ibm.com>
Cc: Michael Neuling <mikey@neuling•org>,
	Vaidyanathan Srinivasan <svaidy@linux•vnet.ibm.com>,
	Shilpasri G Bhat <shilpa.bhat@linux•vnet.ibm.com>,
	"Rafael J. Wysocki" <rafael@kernel•org>,
	Akshay Adiga <akshay.adiga@linux•vnet.ibm.com>,
	linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org,
	linux-pm@vger•kernel.org
Subject: Re: [PATCH 4/5] powernv:idle: Move initialization of sibling pacas to pnv_alloc_idle_core_states
Date: Mon, 10 Jul 2017 14:34:08 +1000	[thread overview]
Message-ID: <877ezgap1b.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170708190012.6c697975@roar.ozlabs.ibm.com>

Nicholas Piggin <npiggin@gmail•com> writes:
> On Fri, 7 Jul 2017 20:34:16 +0530
> Gautham R Shenoy <ego@linux•vnet.ibm.com> wrote:
>> On Fri, Jul 07, 2017 at 01:16:09AM +1000, Nicholas Piggin wrote:
>> > 
>> > Speaking of which... core_idle_state and thread_sibling_pacas are
>> > allocated with kmalloc_node... What happens if we take an SLB miss
>> > in the idle wakeup code on these guys? Nothing good I think. Perhaps
>> > we should put them into the pacas or somewhere in bolted memory.  
>> 
>> Yes, though the SLB miss hasn't yet been encountered in practise so
>> far!
>
> Considering it's a node-affine allocation, it may actually be possible
> to hit in practice on very large memory systems in practice.

You can boot with disable_1tb_segments on the kernel command line to
increase the change of hitting it.

cheers

  reply	other threads:[~2017-07-10  4:34 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-05 16:38 [PATCH 0/5] powernv:idle: Cleanup idle states initialization Gautham R. Shenoy
2017-07-05 16:38 ` [PATCH 1/5] powernv:idle: Move device-tree parsing to one place Gautham R. Shenoy
2017-07-06 14:53   ` Nicholas Piggin
2017-07-07 11:25     ` Gautham R Shenoy
2017-07-08  8:42       ` Nicholas Piggin
2017-07-05 16:38 ` [PATCH 2/5] powernv:idle: Change return type of pnv_probe_idle_states to int Gautham R. Shenoy
2017-07-06 15:01   ` Nicholas Piggin
2017-07-07 12:26     ` Gautham R Shenoy
2017-07-05 16:38 ` [PATCH 3/5] powernv:idle: Define idle init function for power8 Gautham R. Shenoy
2017-07-06 15:06   ` Nicholas Piggin
2017-07-07 12:43     ` Gautham R Shenoy
2017-07-05 16:38 ` [PATCH 4/5] powernv:idle: Move initialization of sibling pacas to pnv_alloc_idle_core_states Gautham R. Shenoy
2017-07-06 15:16   ` Nicholas Piggin
2017-07-07 15:04     ` Gautham R Shenoy
2017-07-08  9:00       ` Nicholas Piggin
2017-07-10  4:34         ` Michael Ellerman [this message]
2017-07-05 16:38 ` [PATCH 5/5] powernv:idle: Disable LOSE_FULL_CONTEXT states when stop-api fails Gautham R. Shenoy
2017-07-06 15:29   ` Nicholas Piggin
2017-07-07 17:37     ` Gautham R Shenoy
2017-07-08  9:05       ` Nicholas Piggin
2017-07-11  5:04         ` Gautham R Shenoy

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=877ezgap1b.fsf@concordia.ellerman.id.au \
    --to=mpe@ellerman$(echo .)id.au \
    --cc=akshay.adiga@linux$(echo .)vnet.ibm.com \
    --cc=ego@linux$(echo .)vnet.ibm.com \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-pm@vger$(echo .)kernel.org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=mikey@neuling$(echo .)org \
    --cc=npiggin@gmail$(echo .)com \
    --cc=rafael@kernel$(echo .)org \
    --cc=shilpa.bhat@linux$(echo .)vnet.ibm.com \
    --cc=svaidy@linux$(echo .)vnet.ibm.com \
    /path/to/YOUR_REPLY

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