linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Oscar Salvador <osalvador@suse.de>
To: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	Pavel Tatashin <pasha.tatashin@soleen.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm,memory_hotplug: Drop unneeded locking
Date: Tue, 1 Jun 2021 12:33:43 +0200	[thread overview]
Message-ID: <20210601103334.GA5927@linux> (raw)
In-Reply-To: <YLYCIZ5XNXGoE95p@dhcp22.suse.cz>

On Tue, Jun 01, 2021 at 11:47:13AM +0200, Michal Hocko wrote:
> While you are touching this and want to drill all the way down then it
> would be reasonable to drop pgdat resize locks as well.
> It is only used in the early boot code and we have one executing thread
> context per numa node during the deferred initialization. I haven't
> checked all potential side effects the lock might have but it sounds
> like there is quite some clean up potential over there.

I am not sure about that. True is that deferred_init_memmap() gets executed
on numa-thread so it's not a problem for itself, but we also have deferred_grow_zone().
It might be that while deferred_init_memmap() is running, we also have calls to
deferred_grow_zone() for the same node and that would cause some trouble wrt.
first_deferred_pfn. I need to double check it, but IIRC, that is the case.


-- 
Oscar Salvador
SUSE L3


      reply	other threads:[~2021-06-01 10:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-31  9:39 Oscar Salvador
2021-05-31 11:37 ` Michal Hocko
2021-06-01  5:17 ` Anshuman Khandual
2021-06-01  7:47   ` Oscar Salvador
2021-06-01  8:02     ` David Hildenbrand
2021-06-01  8:12       ` Oscar Salvador
2021-06-01  9:47         ` Michal Hocko
2021-06-01 10:33           ` Oscar Salvador [this message]

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=20210601103334.GA5927@linux \
    --to=osalvador@suse.de \
    --cc=akpm@linux-foundation.org \
    --cc=anshuman.khandual@arm.com \
    --cc=david@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=pasha.tatashin@soleen.com \
    --cc=vbabka@suse.cz \
    /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