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5 commits

Author SHA1 Message Date
Doug Thompson
87f24c3ac3 drivers/edac: add to edac docs
Updated the EDAC kernel documentation

Signed-off-by:	Doug Thompson <dougthompson@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:57 -07:00
Frithiof Jensen
4f423ddf56 [PATCH] EDAC: Add memory scrubbing controls API to core
This is an attempt of providing an interface for memory scrubbing control in
EDAC.

This patch modifies the EDAC Core to provide the Interface for memory
controller modules to implment.

The following things are still outstanding:

 - K8 is the first implemenation,

   The patch provide a method of configuring the K8 hardware memory scrubber
   via the 'mcX' sysfs directory.  There should be some fallback to a generic
   scrubber implemented in software if the hardware does not support
   scrubbing.

   Or .. the scrubbing sysfs entry should not be visible at all.

 - Only works with SDRAM, not cache,

   The K8 can scrub cache and l2cache also - but I think this is not so
   useful as the cache is busy all the time (one hopes).

   One would also expect that cache scrubbing requires hardware support.

 - Error Handling,

   I would like that errors are returned to the user in "terms of file
   system".

 - Presentation,

   I chose Bandwidth in Bytes/Second as a representation of the scrubbing
   rate for the following reasons:

   I like that the sysfs entries are sort-of textual, related to something
   that makes sense instead of magical values that must be looked up.

   "My People" wants "% main memory scrubbed per hour" others prefer "%
   memory bandwidth used" as representation, "bandwith used" makes it easy to
   calculate both versions in one-liner scripts.

   If one later wants to scrub cache, the scaling becomes wierd for K8
   changing from "blocks of 64 byte memory" to "blocks of 64 cache lines" to
   "blocks of 64 bit".  Using "bandwidth used" makes sense in all three cases,
   (I.M.O.  anyway ;-).

 - Discovery,

   There is no way to discover the possible settings and what they do
   without reading the code and the documentation.

   *I* do not know how to make that work in a practical way.

 - Bugs(??),

   other tools can set invalid values in the memory scrub control register,
   those will read back as '-1', requiring the user to reset the scrub rate.
   This is how *I* think it should be.

 - Afflicting other areas of code,

   I made changes to edac_mc.c and edac_mc.h which will show up globally -
   this is not nice, it would be better that the memory scrubbing fuctionality
   and interface could be entirely contained within the memory controller it
   applies to.

Frithiof Jensen

edac_mc.c and its .h file is a CORE helper module for EDAC
driver modules. This provides the abstraction for device specific
drivers. It is fine to modify this CORE to provide help for
new features of the the drivers

doug thompson

Signed-off-by: Frithiof Jensen <frithiof.jensen@ericson.com>
Signed-off-by: doug thompson <norsk5@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:32 -08:00
Doug Thompson
49c0dab7e6 [PATCH] Fix and enable EDAC sysfs operation
When EDAC was first introduced into the kernel it had a sysfs interface,
but due to some problems it was disabled in 2.6.16 and remained disabled in
2.6.17.

With feedback, several of the control and attribute files of that interface
had some good constructive feedback.  PCI Blacklist/Whitelist was a major
set which has design issues and it has been removed in this patch.  Instead
of storing PCI broken parity status in EDAC, it has been moved to the
pci_dev structure itself by a previous PCI patch.  A future patch will
enable that feature in EDAC by utilizing the pci_dev info.

The sysfs is now enabled in this patch, with a minimal set of control and
attribute files for examining EDAC state and for enabling/disabling the
memory and PCI operations.

The Documentation for EDAC has also been updated to reflect the new state
of EDAC operation.

Signed-off-by:Doug Thompson <norsk5@xmisson.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:25 -07:00
Dave Peterson
f3479816bb [PATCH] EDAC: documentation spelling fixes
Fix spelling errors in EDAC documentation.

Signed-off-by: David S. Peterson <dsp@llnl.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:57:08 -08:00
Alan Cox
da9bb1d27b [PATCH] EDAC: core EDAC support code
This is a subset of the bluesmoke project core code, stripped of the NMI work
which isn't ready to merge and some of the "interesting" proc functionality
that needs reworking or just has no place in kernel.  It requires no core
kernel changes except the added scrub functions already posted.

The goal is to merge further functionality only after the core code is
accepted and proven in the base kernel, and only at the point the upstream
extras are really ready to merge.

From: doug thompson <norsk5@xmission.com>

  This converts EDAC to sysfs and is the final chunk neccessary before EDAC
  has a stable user space API and can be considered for submission into the
  base kernel.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: doug thompson <norsk5@xmission.com>
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:31 -08:00