From: Pavel Machek <pavel@denx.de>
To: Laura Abbott <labbott@fedoraproject.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Vlastimil Babka <vbabka@suse.cz>, Michal Hocko <mhocko@suse.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com,
Kees Cook <keescook@chromium.org>,
linux-pm@vger.kernel.org
Subject: Re: [PATCHv2 2/2] mm/page_poisoning.c: Allow for zero poisoning
Date: Fri, 29 Jan 2016 11:45:43 +0100 [thread overview]
Message-ID: <20160129104543.GA21224@amd> (raw)
In-Reply-To: <1454035099-31583-3-git-send-email-labbott@fedoraproject.org>
Hi!
> By default, page poisoning uses a poison value (0xaa) on free. If this
> is changed to 0, the page is not only sanitized but zeroing on alloc
> with __GFP_ZERO can be skipped as well. The tradeoff is that detecting
> corruption from the poisoning is harder to detect. This feature also
> cannot be used with hibernation since pages are not guaranteed to be
> zeroed after hibernation.
So... this makes kernel harder to debug for performance advantage...?
If so.. how big is the performance advantage?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2016-01-29 10:45 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1454035099-31583-1-git-send-email-labbott@fedoraproject.org>
2016-01-29 2:38 ` [PATCHv2 2/2] mm/page_poisoning.c: Allow for zero poisoning Laura Abbott
2016-01-29 3:55 ` Rafael J. Wysocki
2016-01-29 4:46 ` Kees Cook
2016-01-29 21:32 ` Laura Abbott
2016-01-29 10:45 ` Pavel Machek [this message]
2016-01-29 21:36 ` Laura Abbott
2016-01-30 15:30 ` Pavel Machek
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