Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Wollesen ported the Bluesmoke Memory Controller driver for the Intel
5000X/V/P (Blackford/Greencreek) chipset to the in kernel EDAC model.
This patch incorporates those required changes to the edac_mc.c and edac_mc.h
core files by added new Fully Buffered DIMM interface to the EDAC Core module.
Signed-off-by: eric wollesen <ericw@xmtp.net>
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>
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>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Call sysdev_class_unregister() on failure in edac_sysfs_memctrl_setup()
and decrease identation level for clear logic.
Acked-by: Doug Thompson <norsk5@xmission.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
Remove add_mc_to_global_list(). In next patch, this function will be
reimplemented with different semantics.
1 Reimplement add_mc_to_global_list() with semantics that allow the caller to
determine the ID number for a mem_ctl_info structure. Then modify
edac_mc_add_mc() so that the caller specifies the ID number for the new
mem_ctl_info structure. Platform-specific code should be able to assign the
ID numbers in a platform-specific manner. For instance, on Opteron it makes
sense to have the ID of the mem_ctl_info structure match the ID of the node
that the memory controller belongs to.
2 Modify callers of edac_mc_add_mc() so they use the new semantics.
Signed-off-by: Doug Thompson <norsk5@xmission.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>
Change MC drivers from using CVS revision strings for their version number,
Now each driver has its own local string.
Remove some PCI dependencies from the core EDAC module. Made the code 'struct
device' centric instead of 'struct pci_dev' Most of the code changes here are
from a patch by Dave Jiang. It may be best to eventually move the
PCI-specific code into a separate source file.
Signed-off-by: Doug Thompson <norsk5@xmission.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>
Fix a lot of typos. Eyeballed by jmc@ in OpenBSD.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change all instances of EXPORT_SYMBOL() in the core EDAC module to
EXPORT_SYMBOL_GPL().
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Cosmetic indentation/formatting cleanup for EDAC code. Make sure we
are using tabs rather than spaces to indent, etc.
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>
Fix EDAC code so EXPORT_SYMBOL comes after the function that is being
exported. This is to maintain consistency with the rest of the kernel.
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>
- Fix code so we always hold mem_ctls_mutex while we are stepping
through the list of mem_ctl_info structures. Otherwise bad things
may happen if one task is stepping through the list while another
task is modifying it. We may eventually want to use reference
counting to manage the mem_ctl_info structures. In the meantime we
may as well fix this bug.
- Don't disable interrupts while we are walking the list of
mem_ctl_info structures in check_mc_devices(). This is unnecessary.
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>
- After we unregister a kobject, wait for our kobject release method
to call complete(). This causes us to wait until the kobject
reference count reaches 0. Otherwise, a task accessing the EDAC
sysfs interface can hold the reference count above 0 until after the
EDAC module has been unloaded. When the reference count finally
drops to 0, this will result in an attempt to call our release
method inside the EDAC module after the module has already been
unloaded.
This isn't the best fix, since a process can get stuck sleeping forever
uninterruptibly if the user does the following:
rmmod my_module < /sys/my_sysfs/file
I'll go back and implement a better fix later. However this should
be ok for now.
- Call edac_remove_sysfs_mci_device() from edac_mc_del_mc() rather
than from edac_mc_free(). Since edac_mc_add_mc() calls
edac_create_sysfs_mci_device(), edac_mc_del_mc() should call
edac_remove_sysfs_mci_device().
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Remove calls to kobject_init(). These are unnecessary because
kobject_register() calls kobject_init().
- Remove extra calls to kobject_put(). When we call
kobject_unregister(), this releases our reference to the kobject.
The extra calls to kobject_put() may cause the reference count to
drop to 0 while a kobject is still in use.
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is part 2 of a 2-part patch set.
Fix edac_mc_add_mc() so it cleans up properly if call to
edac_create_sysfs_mci_device() fails.
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>
This is part 1 of a 2-part patch set. The code changes are split into
two parts to make the patches more readable.
Move complete_mc_list_del() and del_mc_from_global_list() so we can
call del_mc_from_global_list() from edac_mc_add_mc() without forward
declarations. Perhaps using forward declarations would be better?
I'm doing things this way because the rest of the code is missing
them.
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>
Fix xxx_probe1() functions so they call xxx_get_error_info() functions
to clear initial errors. This is simpler and cleaner than duplicating
the low-level code for accessing PCI config space.
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>
This implements the following idea:
On Monday 30 January 2006 19:22, Eric W. Biederman wrote:
> One piece missing from this conversation is the issue that we need errors
> in a uniform format. That is why edac_mc has helper functions.
>
> However there will always be errors that don't fit any particular model.
> Could we add a edac_printk(dev, ); That is similar to dev_printk but
> prints out an EDAC header and the device on which the error was found?
> Letting the rest of the string be user specified.
>
> For actual control that interface may be to blunt, but at least for people
> looking in the logs it allows all of the errors to be detected and
> harvested.
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>
This patch was originally posted by Christoph Hellwig (see
http://lkml.org/lkml/2006/2/14/331):
"Christoph Hellwig" <hch@lst.de> wrote:
> Use the kthread_ API instead of opencoding lots of hairy code for kernel
> thread creation and teardown, including tasklist_lock abuse.
>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Cc: <dave_peterson@pobox.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>
- Disable the EDAC sysfs code. The sysfs interface that EDAC presents to
user space needs more thought, and is likely to change substantially.
Therefore disable it for now so users don't start depending on it in its
current form.
- Disable the default behavior of calling panic() when an uncorrectible
error is detected (since for now, there is no sysfs interface that allows
the user to configure this behavior).
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Disable (via ugly #if 0's) the 3 sysfs files that I think by now we all
agree are very much wrong. These files shouldn't become part of the ABI by
the 2.6.16 release, so I rather have this minimal patch merged to disable
them for now, the real fix can then come during the 2.6.17 devel window.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
By including version.h edac_mc was rebuilding on every incremental build.
Which defeats the point of incremental builds.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.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>
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>
