linux-kernel - RE: [PATCH] mm: Introduce kernelcore=reliable option

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]

Date:	Wed, 21 Oct 2015 18:17:06 +0000
From:	"Luck, Tony" <tony.luck@...el.com>
To:	Taku Izumi <izumi.taku@...fujitsu.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>
CC:	"qiuxishi@...wei.com" <qiuxishi@...wei.com>,
	"kamezawa.hiroyu@...fujitsu.com" <kamezawa.hiroyu@...fujitsu.com>,
	"mel@....ul.ie" <mel@....ul.ie>,
	"akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
	"Hansen, Dave" <dave.hansen@...el.com>,
	"matt@...eblueprint.co.uk" <matt@...eblueprint.co.uk>
Subject: RE: [PATCH] mm: Introduce kernelcore=reliable option

+	if (reliable_kernelcore) {
+		for_each_memblock(memory, r) {
+			if (memblock_is_mirror(r))
+				continue;

Should we have a safety check here that there is some mirrored memory?  If you give
the kernelcore=reliable option on a machine which doesn't have any mirror configured,
then we'll mark all memory as removable.  What happens then?  Do kernel allocations
fail?  Or do they fall back to using removable memory?

Is there a /proc or /sys file that shows the current counts for the removable zone?  I just
tried this patch with a high percentage of memory marked as mirror ... but I'd like to see
how much is actually being used to tune things a bit.

-Tony
--
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/