linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Pavel Tatashin <pasha.tatashin@oracle.com>
To: mhocko@kernel.org
Cc: osalvador@techadventures.net,
	Andrew Morton <akpm@linux-foundation.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	aaron.lu@intel.com, iamjoonsoo.kim@lge.com,
	LKML <linux-kernel@vger.kernel.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	osalvador@suse.de
Subject: Re: [PATCH v2 5/5] mm/page_alloc: Only call pgdat_set_deferred_range when the system boots
Date: Thu, 19 Jul 2018 10:27:44 -0400	[thread overview]
Message-ID: <CAGM2reZ-+njLtZSnNpry11frg85KmMk4WWxGdaqk1o4BUJVO1w@mail.gmail.com> (raw)
In-Reply-To: <20180719140308.GG7193@dhcp22.suse.cz>

On Thu, Jul 19, 2018 at 10:03 AM Michal Hocko <mhocko@kernel.org> wrote:
>
> On Thu 19-07-18 15:58:59, Oscar Salvador wrote:
> > On Thu, Jul 19, 2018 at 03:46:22PM +0200, Michal Hocko wrote:
> > > On Thu 19-07-18 15:27:40, osalvador@techadventures.net wrote:
> > > > From: Oscar Salvador <osalvador@suse.de>
> > > >
> > > > We should only care about deferred initialization when booting.
> > >
> > > Again why is this worth doing?
> >
> > Well, it is not a big win if that is what you meant.
> >
> > Those two fields are only being used when dealing with deferred pages,
> > which only happens at boot time.
> >
> > If later on, free_area_init_node gets called from memhotplug code,
> > we will also set the fields, although they will not be used.
> >
> > Is this a problem? No, but I think it is more clear from the code if we
> > see when this is called.
> > So I would say it was only for code consistency.
>
> Then put it to the changelog.
>
> > If you think this this is not worth, I am ok with dropping it.
>
> I am not really sure. I am not a big fan of SYSTEM_BOOTING global
> thingy so I would rather not spread its usage.

I agree, I do not think this patch is necessary. Calling
pgdat_set_deferred_range() does not hurt in hotplug context, and it is
cheap too. SYSTEM_BOOTING sometimes useful, but it is better to use it
only where necessary, where without this "if" we will encounter some
bugs.

Thank you,
Pavel

  reply	other threads:[~2018-07-19 14:28 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-19 13:27 [PATCH v2 0/5] Refactor free_area_init_node/free_area_init_core osalvador
2018-07-19 13:27 ` [PATCH v2 1/5] mm/page_alloc: Move ifdefery out of free_area_init_core osalvador
2018-07-19 13:27 ` [PATCH v2 2/5] mm: access zone->node via zone_to_nid() and zone_set_nid() osalvador
2018-07-19 13:40   ` Michal Hocko
2018-07-19 13:44     ` Pavel Tatashin
2018-07-19 13:47       ` Michal Hocko
2018-07-19 13:27 ` [PATCH v2 3/5] mm/page_alloc: Optimize free_area_init_core osalvador
2018-07-19 13:44   ` Michal Hocko
2018-07-19 14:03     ` Oscar Salvador
2018-07-19 15:15       ` Michal Hocko
2018-07-19 20:52         ` Oscar Salvador
2018-07-20 10:03           ` Oscar Salvador
2018-07-23  8:35             ` Michal Hocko
2018-07-23 11:42               ` Oscar Salvador
2018-07-23  8:30           ` Michal Hocko
2018-07-19 13:27 ` [PATCH v2 4/5] mm/page_alloc: Inline function to handle CONFIG_DEFERRED_STRUCT_PAGE_INIT osalvador
2018-07-19 13:45   ` Michal Hocko
2018-07-19 13:27 ` [PATCH v2 5/5] mm/page_alloc: Only call pgdat_set_deferred_range when the system boots osalvador
2018-07-19 13:46   ` Michal Hocko
2018-07-19 13:58     ` Oscar Salvador
2018-07-19 14:03       ` Michal Hocko
2018-07-19 14:27         ` Pavel Tatashin [this message]
2018-07-19 15:01           ` Oscar Salvador

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=CAGM2reZ-+njLtZSnNpry11frg85KmMk4WWxGdaqk1o4BUJVO1w@mail.gmail.com \
    --to=pasha.tatashin@oracle.com \
    --cc=aaron.lu@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=osalvador@suse.de \
    --cc=osalvador@techadventures.net \
    --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;
as well as URLs for NNTP newsgroup(s).