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:	Mon, 2 Jun 2014 16:22:19 +0000
From:	"Luck, Tony" <tony.luck@...el.com>
To:	Steven Rostedt <rostedt@...dmis.org>
CC:	Borislav Petkov <bp@...en8.de>,
	"Chen, Gong" <gong.chen@...ux.intel.com>,
	"m.chehab@...sung.com" <m.chehab@...sung.com>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 5/7 v6] trace, RAS: Add eMCA trace event interface

>> All of this stuff only applies to server systems - so quibbling over
>> a handful of *bytes* in an error record on a system that has tens,
>> hundreds or even thousands of *gigabytes* of memory seems
>> a bit pointless.
>
> But there's still only a limited number of bytes in the ring buffer no
> matter what the system, thus we still need to quibble over it.

To which I'll counter that the trace ring buffer can handle tracing of
events like page faults and context switches (can't it?) that happen
at a rate of thousands per second.  Our eMCA records will normally
happen at a rate of X per month (where X may well be less than one).
If there is a storm of errors - we disable CMCI interrupts and revert
to polling.  We declare a "storm" as just 15 events in a second. If we
switch to polling, then we won't poll faster than once per second.

So worst case is that we are seeing some steady flow of events that
don't quite trigger the storm detector ... about 14 events per second.

-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/

Powered by blists - more mailing lists