linux-kernel - Re: [PATCH v2 1/2] mm/page_alloc: Do not calculate node's total pages and memmap pages when empty

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YrLY1ru0qrvZfqU2@FVFYT0MHHV2J.usts.net>
Date:   Wed, 22 Jun 2022 16:54:46 +0800
From:   Muchun Song <songmuchun@...edance.com>
To:     David Hildenbrand <david@...hat.com>
Cc:     Oscar Salvador <osalvador@...e.de>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...nel.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] mm/page_alloc: Do not calculate node's total
 pages and memmap pages when empty

On Wed, Jun 22, 2022 at 10:31:12AM +0200, David Hildenbrand wrote:
> On 22.06.22 05:56, Muchun Song wrote:
> > On Wed, Jun 22, 2022 at 05:47:22AM +0200, Oscar Salvador wrote:
> >> On Tue, Jun 21, 2022 at 09:44:47AM +0200, David Hildenbrand wrote:
> >>>
> >>>
> >>> It's worth noting that the check in pgdat_is_empty() is slightly
> >>> different. I *think* it doesn't matter in practice, yet I wonder if we
> >>> should simply fixup (currently unused) pgdat_is_empty().
> >>
> >> I guess we could change it to
> >>
> >>  static inline bool pgdat_is_empty(pg_data_t *pgdat)
> >>  {
> >> 	 return node_start_pfn(pgdat->node_id) == node_end_pfn(pgdat->node_id)
> >>  }
> >>
> >> ? And maybe even rename it to to node_is_empty (not sure why but I tend to like
> > 
> > At least I like this name (node_is_empty) as well.
> > 
> 
> Let's try keeping it consistent. I think node_is_empty() might indicate
> that we're punching in a node id instead of a pgdat.
>

I suspect Oscar will change the argument to "nid" as well, like:

static inline bool node_is_empty(int nid)
{
	return node_start_pfn(nid) == node_end_pfn(nid);
}

Does this look good?

Thanks.
 
> 
> -- 
> Thanks,
> 
> David / dhildenb
> 
>