linux-kernel - Re: [PATCH v2 0/9] page_owner improvements for debugging

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: <20151125143010.GI27283@dhcp22.suse.cz>
Date:	Wed, 25 Nov 2015 15:30:10 +0100
From:	Michal Hocko <mhocko@...nel.org>
To:	Vlastimil Babka <vbabka@...e.cz>
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Joonsoo Kim <iamjoonsoo.kim@....com>,
	Minchan Kim <minchan@...nel.org>,
	Sasha Levin <sasha.levin@...cle.com>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Mel Gorman <mgorman@...e.de>
Subject: Re: [PATCH v2 0/9] page_owner improvements for debugging

On Tue 24-11-15 13:36:12, Vlastimil Babka wrote:
[...]
> For the last point, Kirill requested a human readable printing of gfp_mask and
> migratetype after v1. At that point it probably makes a lot of sense to do the
> same for page alloc failure and OOM warnings. The flags have been undergoing
> revisions recently, and we might be getting reports from various kernel
> versions that differ. The ./scripts/gfp-translate tool needs to be pointed at
> the corresponding sources to be accurate.  The downside is potentially breaking
> scripts that grep these warnings, but it's not a first change done there over
> the years.

Yes this is very helpful! Thanks for doing this.
 
> Note I'm not entirely happy about the dump_gfpflag_names() implementation, due
> to usage of pr_cont() unreliable on SMP (and I've seen spurious newlines in
> dmesg output, while being correct on serial console or /var/log/messages).
> It also doesn't allow plugging the gfp_mask translation into
> /sys/kernel/debug/page_owner where it also could make sense. Maybe a new
> *printf formatting flag?

I wouldn't object. gfp_mask has its own "type" so having a specific
formatter sounds like a good idea to me.

-- 
Michal Hocko
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/