Commit Graph

98924 Commits

Author SHA1 Message Date
Heiko Carstens
e0bc24958e [S390] Add support for memory hot-add via sclp.
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Heiko Carstens
421c175c4d [S390] Add support for memory hot-add.
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Akinobu Mita
0788fea4d5 [S390] s390: use memory_read_from_buffer()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Akinobu Mita
a29591c475 [S390] s390: use simple_read_from_buffer()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Akinobu Mita
d9cef21af0 [S390] s390/cio: use memory_read_from_buffer()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:15 +02:00
Akinobu Mita
7785857a5a [S390] s390/vmcp: use simple_read_from_buffer()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:15 +02:00
Julia Lawall
3ca1c9907a [S390] drivers/s390: Eliminate NULL test and memset after alloc_bootmem
As noted by Akinobu Mita in patch b1fceac2b9,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

 drivers/s390/char/raw3270.c  |   11 +----------
 drivers/s390/char/sclp_con.c |    2 --
 2 files changed, 1 insertion(+), 12 deletions(-)

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- memset(E,0,E1);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:15 +02:00
Julia Lawall
402a3998ba [S390] arch/s390: Eliminate NULL test and memset after alloc_bootmem
As noted by Akinobu Mita in patch b1fceac2b9,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

 arch/s390/kernel/topology.c |    2 --
 1 file changed, 2 deletions(-)

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- memset(E,0,E1);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:14 +02:00
Heiko Carstens
9789db08c0 [S390] Add sched.h include to asm-s390/pgtable.h.
Some macros in pgtable.h access members from struct task_struct.
Currently always works since sched.h seems always to be included
before asm/pgtable.h. Unfortunately that is not anymore true with
Jeremy Fitzhardinge's ptep_modify_prot transaction abstraction patch.
So fix this.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:14 +02:00
Ralph Wuerthner
d8c33d32a4 [S390] zcrypt: Add additional card IDs to CEX2C and CEX2A
Add support for new micro code load of CEX2C and CEX2A adapters,
which uses different IDs.  This patch just adds the IDs to the
existing drivers.

Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:14 +02:00
Hendrik Brueckner
a0443fbb46 [S390] Extra Kernel Parameters via VMPARM
Now it is possible to specify additional kernel parameters on the IPL
command line using the IPL PARM option.
If the Linux system is already running, the new reipl sysfs attribute
'parm' can be used to change kernel parameters for the next reboot.
Examples:
  IPL    C PARM dasd=1234 root=/dev/dasda1
  IPL 1234 PARM savesys=mylnxnss
  echo "init=/bin/bash" > /sys/firmware/reipl/ccw/parm

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:14 +02:00
Felix Beck
fe13723061 [S390] ap: Use high-resolution timer for polling
The ap poll mechanism is converted to use a high-resolution timer for
polling. This allows more specific polling. With this a new sysfs
attribute is introduced to specify the polling rate in nanoseconds.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:13 +02:00
Peter Oberparleiter
ad211790c0 [S390] sclp: simplify vt220 cleanup logic
Fix a number of sclp_vt220 cleanup problems:
* fix list_empty check after list_del()
* mark init-only flag as __initdata
* remove implicit dependency between slab_available() and num_pages
* straighten multiple init handling (use init count)

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:13 +02:00
Heiko Carstens
773922e1da [S390] idle: remove idle notifier chain.
The idle notifier chain consists of at most one element. So there's
no point in having a notifier chain. Remove it and directly call the
function.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:13 +02:00
Cornelia Huck
9d92a7e1b0 [S390] cio: Add chsc subchannel driver.
This patch adds a driver for subchannels of type chsc.

A device /dev/chsc is created which may be used to issue ioctls to:
- obtain information about the machine's I/O configuration
- dynamically change the machine's I/O configuration via
  asynchronous chsc commands

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:12 +02:00
Peter Oberparleiter
683c5418e6 [S390] cio: suppress chpid event in case of configure error
Do not send CHP_ONLINE/CHP_OFFLINE events to subchannel drivers when a
channel-path configure request failed.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:12 +02:00
Cornelia Huck
f08adc008d [S390] css: Use css_device_id for bus matching.
css_device_id exists, so use it for determining the right driver
(and add a match_flags which is always 1 for valid types).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:12 +02:00
Cornelia Huck
99611f8717 [S390] cio: Repair chpid event handling.
Passing the affected chpid in chp_event() worked only by
chance since chpid is the first element in res_acc_data.
Make it work properly by generalizing res_acc_data as
chp_link and always passing around a properly filled out
chp_link structure in chp_event().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:11 +02:00
Cornelia Huck
6ef556ccc8 [S390] cio: Use isc_{register,unregister}.
Use the new isc registration functions for all places that need
an I/O interruption subclass.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:11 +02:00
Sebastian Ott
fcc6ab335b [S390] cio: introduce isc_(un)register functions.
This interface makes it easy for drivers to register usage of different
I/O interruption subclasses without needing to worry about possible
other users of the same isc.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:11 +02:00
Cornelia Huck
da7c5af828 [S390] cio: Allow adapter interrupt handlers per isc.
Enhance the adapter interruption API so that device drivers can
register a handler for a specific interruption subclass. This
will allow different device drivers to move to differently
prioritized subclasses in order to avoid congestion.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:10 +02:00
Cornelia Huck
3a3fc29a6d [S390] cio: Introduce abstract isc definitions.
Replace the numeric values for I/O interruption subclass usage
with abstract definitions and collect them all in asm/isc.h.
This gives us a better overview of which iscs are actually used
and makes it possible to better spread out isc usage in the
future.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:10 +02:00
Cornelia Huck
75784c0087 [S390] cio: Get rid of css_characteristics_avail.
Checking for the validity of the css_*_characteristics is
superfluous since they stay 0 for non-successful scsc.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:10 +02:00
Martin Schwidefsky
d2fec59551 [S390] stp support.
Add support for clock synchronization with the server time protocol.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:09 +02:00
Heiko Carstens
761cdf6aac [S390] initrd vs bss section clearing.
In case the initrd is located within the bss section it will be
overwritten when the section is cleared. To prevent this just move
the initrd right behind the bss section if it starts within the
section.
The current code already moves the initrd if the bootmem allocator
bitmap would overwrite it. With this patch we should be safe against
initrd corruptions.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:09 +02:00
Martin Schwidefsky
63506c4198 [S390] Introduce user_regset accessors for s390
Add the user_regset definitions for normal and compat processes, replace
the dump_regs core dump cruft with the generic CORE_DUMP_USER_REGSET and
replace binfmt_elf32.c with the generic compat_binfmt_elf.c implementation.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:09 +02:00
Sebastian Ott
ae437a452e [S390] cio: remove lock from ccw_device_oper_notify.
Remove unnecessary ccw device locking inside ccw_device_oper_notify.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:08 +02:00
Peter Oberparleiter
23f6268947 [S390] cio: provide helper functions for fcx enabled I/O
Provide functions which can be used to incrementally construct fcx
enabled I/O control blocks.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:08 +02:00
Peter Oberparleiter
83262d6349 [S390] cio: provide functions for fcx enabled I/O
Provide functions for assembling and starting fcx enabled I/O request
blocks.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:08 +02:00
Peter Oberparleiter
23d805b647 [S390] cio: introduce fcx enabled scsw format
Extend the scsw data structure to the format required by fcx. Also
provide helper functions for easier access to fields which are present
in both the traditional as well as the modified format.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:07 +02:00
Peter Oberparleiter
4f2bd92e3b [S390] cio: introduce fcx bit to chsc characteristics
Introduce fcx bit to chsc characteristics.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:07 +02:00
Cornelia Huck
b3a686f47a [S390] cio: Base message subchannel handling.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:06 +02:00
Cornelia Huck
44a1c19e3b [S390] cio: Export some symbols for modular css drivers.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:06 +02:00
Cornelia Huck
c11561897a [S390] cio: Cleanup crw interface.
Eliminate the need for the machine check handler to call into
the common I/O layer directly by introducing an interface to
register handlers for crws per rsc.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:06 +02:00
Cornelia Huck
c820de39bd [S390] cio: Rework css driver.
Rework the css driver methods to provide sane callbacks for
subchannels of all types.

As a bonus, this cleans up and simplyfies the machine check
handling for I/O subchannels a lot.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:05 +02:00
Cornelia Huck
7e9db9eaef [S390] cio: Introduce modalias for css bus.
Add modalias and subchannel type attributes for all subchannels.
I/O subchannel specific attributes are now created in
io_subchannel_probe(). modalias and subchannel type are also
added to the uevent for the css bus. Also make the css modalias
known.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:05 +02:00
Cornelia Huck
0ae7a7b250 [S390] cio: Register all subchannels.
Register all valid subchannels, not only I/O subchannels.
Move I/O subchannel specific initialization to io_subchannel_probe().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:05 +02:00
Heiko Carstens
b4a33acb69 [S390] Remove ipldelay kernel parameter.
Using the ipldelay kernel parameter leads to a crash at IPL time.
Since this is broken since a long time it looks like nobody is using
it anymore. So remove it instead of fixing it.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:01 +02:00
Heiko Carstens
b9732ca1cb [S390] sclp: fix possible deadlock on cpu rescan.
smp_rescan_cpus() calls get_online_cpus() from a multithreaded
workqueue context. This may deadlock. This is the same bug as in
arch/s390/kernel/topology.c. This patch can be reverted as soon as
Oleg's patch gets merged.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:01 +02:00
Gerald Schaefer
0c3252d58c [S390] make appldata compile w/o CONFIG_SWAP
Avoid compile error by using EXPORT_SYMBOL_GPL(si_swapinfo) only if
CONFIG_SWAP is set.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:02:00 +02:00
Heiko Carstens
887d935a84 [S390] sclp: keep facility mask up to date.
In case the supported sclp facilities change
the new mask should be saved.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:00 +02:00
Ursula Braun
bb0ca330a7 [S390] qdio: Repair timeout handling for qdio_shutdown
If qdio shutdown runs in parallel with a channel error,
the qdio_timeout_handler might not be triggered.
In this case neither state INACTIVE nor state ERR
is reached and the following wait_event hangs forever.
Solution: do not make use of ccw_device_set_timeout(),
but add a timeout to the following wait_event.
And make sure, wake_up is called in case of an
i/o error on the qdio-device.

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:01:59 +02:00
Michael Ernst
b1c02d9110 [S390] cio: Use locks when accessing /sys/firmware/cpi data.
Mutex locks are used to avoid problems when /sys/firmware/cpi data
are accessed to in parallel.

Signed-off-by: Michael Ernst <mernst@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:01:59 +02:00
Cornelia Huck
9689b336e1 [S390] cio: Clear correct bit in cio_release_console().
Fallout from the console isc 7 -> 1 change.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-14 10:01:59 +02:00
Linus Torvalds
bce7f793da Linux 2.6.26 2008-07-13 14:51:29 -07:00
Li Zefan
ec229e8300 devcgroup: fix permission check when adding entry to child cgroup
# cat devices.list
 c 1:3 r
 # echo 'c 1:3 w' > sub/devices.allow
 # cat sub/devices.list
 c 1:3 w

As illustrated, the parent group has no write permission to /dev/null, so
it's child should not be allowed to add this write permission.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-13 12:51:18 -07:00
Li Zefan
17d213f806 devcgroup: always show positive major/minor num
# echo "b $((0x7fffffff)):$((0x80000000)) rwm" > devices.allow
 # cat devices.list
 b 214748364:-21474836 rwm

though a major/minor number of 0x800000000 is meaningless, we
should not cast it to a negative value.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-13 12:51:18 -07:00
Jiri Pirko
0302c01b4b Documentation/HOWTO: correct wrong kernel bugzilla FAQ URL
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-13 12:51:18 -07:00
Linus Torvalds
3b5c6b8349 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  cpusets, hotplug, scheduler: fix scheduler domain breakage
2008-07-13 11:03:59 -07:00
Dmitry Adamushko
3e84050c81 cpusets, hotplug, scheduler: fix scheduler domain breakage
Commit f18f982ab ("sched: CPU hotplug events must not destroy scheduler
domains created by the cpusets") introduced a hotplug-related problem as
described below:

Upon CPU_DOWN_PREPARE,

  update_sched_domains() -> detach_destroy_domains(&cpu_online_map)

does the following:

/*
 * Force a reinitialization of the sched domains hierarchy. The domains
 * and groups cannot be updated in place without racing with the balancing
 * code, so we temporarily attach all running cpus to the NULL domain
 * which will prevent rebalancing while the sched domains are recalculated.
 */

The sched-domains should be rebuilt when a CPU_DOWN ops. has been
completed, effectively either upon CPU_DEAD{_FROZEN} (upon success) or
CPU_DOWN_FAILED{_FROZEN} (upon failure -- restore the things to their
initial state). That's what update_sched_domains() also does but only
for !CPUSETS case.

With f18f982ab, sched-domains' reinitialization is delegated to
CPUSETS code:

cpuset_handle_cpuhp() -> common_cpu_mem_hotplug_unplug() ->
rebuild_sched_domains()

Being called for CPU_UP_PREPARE and if its callback is called after
update_sched_domains()), it just negates all the work done by
update_sched_domains() -- i.e. a soon-to-be-offline cpu is included in
the sched-domains and that makes it visible for the load-balancer
while the CPU_DOWN ops. is in progress.

__migrate_live_tasks() moves the tasks off a 'dead' cpu (it's already
"offline" when this function is called).

try_to_wake_up() is called for one of these tasks from another CPU ->
the load-balancer (wake_idle()) picks up a "dead" CPU and places the
task on it. Then e.g. BUG_ON(rq->nr_running) detects this a bit later
-> oops.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: miaox@cn.fujitsu.com
Cc: rostedt@goodmis.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-13 11:37:02 +02:00