keventd is inappropriate for running block request queues because keventd
itself can get blocked on disk I/O.  Via call_usermodehelper()'s vfork and,
presumably, GFP_KERNEL allocations.

So create a new gang of kernel threads whose mandate is for running low-level
disk operations.  It must ever block on disk IO, so any memory allocations
should be GFP_NOIO.

We mainly use it for running unplug operations from interrupt context.

From: Nick Piggin <piggin@cyberone.com.au>

The batch_requests function got lost during the merge of the dynamic request
allocation patch.

We need it for the anticipatory scheduler - when the number of threads
exceeds the number of requests, the anticipated-upon task will undesirably
sleep in get_request_wait().

And apparently some block devices which use small requests need it so they
string a decent number together.

Jens has acked this patch.

From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>

This patch proposes a performance fix for the current IPC semaphore
implementation.

There are two shortcoming in the current implementation:
try_atomic_semop() was called two times to wake up a blocked process,
once from the update_queue() (executed from the process that wakes up
the sleeping process) and once in the retry part of the blocked process
(executed from the block process that gets woken up).

A second issue is that when several sleeping processes that are eligible
for wake up, they woke up in daisy chain formation and each one in turn
to wake up next process in line.  However, every time when a process
wakes up, it start scans the wait queue from the beginning, not from
where it was last scanned.  This causes large number of unnecessary
scanning of the wait queue under a situation of deep wait queue.
Blocked processes come and go, but chances are there are still quite a
few blocked processes sit at the beginning of that queue.

What we are proposing here is to merge the portion of the code in the
bottom part of sys_semtimedop() (code that gets executed when a sleeping
process gets woken up) into update_queue() function.  The benefit is two
folds: (1) is to reduce redundant calls to try_atomic_semop() and (2) to
increase efficiency of finding eligible processes to wake up and higher
concurrency for multiple wake-ups.

We have measured that this patch improves throughput for a large
application significantly on a industry standard benchmark.

This patch is relative to 2.5.72.  Any feedback is very much
appreciated.

Some kernel profile data attached:

  Kernel profile before optimization:
  -----------------------------------------------
                0.05    0.14   40805/529060      sys_semop [133]
                0.55    1.73  488255/529060      ia64_ret_from_syscall
[2]
[52]     2.5    0.59    1.88  529060         sys_semtimedop [52]
                0.05    0.83  477766/817966      schedule_timeout [62]
                0.34    0.46  529064/989340      update_queue [61]
                0.14    0.00 1006740/6473086     try_atomic_semop [75]
                0.06    0.00  529060/989336      ipcperms [149]
  -----------------------------------------------

                0.30    0.40  460276/989340      semctl_main [68]
                0.34    0.46  529064/989340      sys_semtimedop [52]
[61]     1.5    0.64    0.87  989340         update_queue [61]
                0.75    0.00 5466346/6473086     try_atomic_semop [75]
                0.01    0.11  477676/576698      wake_up_process [146]
  -----------------------------------------------
                0.14    0.00 1006740/6473086     sys_semtimedop [52]
                0.75    0.00 5466346/6473086     update_queue [61]
[75]     0.9    0.89    0.00 6473086         try_atomic_semop [75]
  -----------------------------------------------

  Kernel profile with optimization:

  -----------------------------------------------
                0.03    0.05   26139/503178      sys_semop [155]
                0.46    0.92  477039/503178      ia64_ret_from_syscall
[2]
[61]     1.2    0.48    0.97  503178         sys_semtimedop [61]
                0.04    0.79  470724/784394      schedule_timeout [62]
                0.05    0.00  503178/3301773     try_atomic_semop [109]
                0.05    0.00  503178/930934      ipcperms [149]
                0.00    0.03   32454/460210      update_queue [99]
  -----------------------------------------------
                0.00    0.03   32454/460210      sys_semtimedop [61]
                0.06    0.36  427756/460210      semctl_main [75]
[99]     0.4    0.06    0.39  460210         update_queue [99]
                0.30    0.00 2798595/3301773     try_atomic_semop [109]
                0.00    0.09  470630/614097      wake_up_process [146]
  -----------------------------------------------
                0.05    0.00  503178/3301773     sys_semtimedop [61]
                0.30    0.00 2798595/3301773     update_queue [99]
[109]    0.3    0.35    0.00 3301773         try_atomic_semop [109]
  -----------------------------------------------=20

Both number of function calls to try_atomic_semop() and update_queue()
are reduced by 50% as a result of the merge.  Execution time of
sys_semtimedop is reduced because of the reduction in the low level
functions.

From: Matthew Wilcox <willy@debian.org>

ppc64 oopses on boot because pci_scan_bus_parented() is unexpectedly
returning NULL.  Change pci_scan_bus_parented() to correctly handle
overlapping PCI bus numbers on different domains.

into home.osdl.org:/home/torvalds/v2.5/linux

into samba.org:/home/paulus/kernel/for-linus-ppc

If a signal is sent via kill() or tkill() the kernel fills in the wrong
PID value in the siginfo_t structure (obviously only if the handler has
SA_SIGINFO set).

POSIX specifies the the si_pid field is filled with the process ID, and
in Linux parlance that's the "thread group" ID, not the thread ID.

event (ie SIGSEGV, SIGFPE etc that happens as a result of a
trap as opposed to an external event), if the signal is
blocked we will not invoce a signal handler, we will just
kill the thread with the signal.

This is equivalent to what we do in the SIG_IGN case: you
cannot ignore or block synchronous signals, and if you try,
we'll just have to kill you.

We don't want to handle endless recursive faults, which the
old behaviour easily led to if the stack was bad, for example.

since some drivers seem to be unhappy about the 10-byte
version. 

The subsystem configuration can override this (eg USB or
ide-scsi).

- By default, do not try to probe the bus if the mainboard does not
  seems to support EISA (allow this behaviour to be changed through a
  command-line option).

- Use parent bridge device dma_mask as default for each discovered
  device.

- Probe the right number of EISA slots on PA-RISC. No more, no less.

- Now reserves I/O ranges according to EISA specs (four 256 bytes
  regions instead of a single 4KB region).

- By default, do not try to probe the bus if the mainboard does not
  seems to support EISA (allow this behaviour to be changed through a
  command-line option).

- Use parent bridge device dma_mask as default for each discovered
  device.

- Allow devices to be enabled or disabled from the kernel command line
  (useful for non-x86 platforms where the firmware simply disable
  devices it doesn't know about...).

into home.osdl.org:/home/torvalds/v2.5/linux

trigger as per the "bk help triggers" suggestion, so that
we'll see any new triggers showing up in the tree.

Make it so.

  - Make use of the open intents to improve close-to-open
    cache consistency. Only force data cache revalidation when
    we're doing an open().

  - Add true exclusive create to NFSv3.

  - Optimize away the redundant ->lookup() to check for an
    existing file when we know that we're doing NFSv3 exclusive
    create.

  - Optimize away all ->permission() checks other than those for
    path traversal, open(), and sys_access().

   - Make the VFS pass the struct nameidata as an optional parameter
     to the permission() inode operation.

   - Patch may_create()/may_open() so it passes the struct nameidata from
     vfs_create()/open_namei() as an argument to permission().

   - Add an intent flag for the sys_access() function.

  - Make the VFS pass the struct nameidata as an optional argument
    to the create inode operation.
  - Patch vfs_create() to take a struct nameidata as an optional
    argument.

 - Add open intent information to the 'struct nameidata'.
 - Pass the struct nameidata as an optional parameter to the
   lookup() inode operation.
 - Pass the struct nameidata as an optional parameter to the
   d_revalidate() dentry operation.
 - Make link_path_walk() set the LOOKUP_CONTINUE flag in nd->flags instead
   of passing it as an extra parameter to d_revalidate().
 - Make open_namei(), and sys_uselib() set the open()/create() intent
   data.

into samba.org:/home/paulus/kernel/for-linus-ppc

into samba.org:/home/paulus/kernel/for-linus-ppc

into samba.org:/home/paulus/kernel/for-linus-ppc

Via irq routing has a funky PIRQD location.  I checked my datasheets
and, yep, this is correct all the way back to via686a.
This bug existed for _ages_.  I wonder if I created it, even...

into home.osdl.org:/home/torvalds/v2.5/linux

follow by splitting it into two functions: one that calculates
the position, and the other that actually reads the inode
block off the disk.

uses it for now, but I needed it for some tuning tests,
and it is potentially useful for others.

into kroah.com:/home/linux/BK/pci-2.5

Based on a patch written by Dan Aloni <da-x@gmx.net>

Based on a patch written by Dan Aloni <da-x@gmx.net>

Based on a patch written by Dan Aloni <da-x@gmx.net>

This patch fixes a bad declaration of jiffies in timer_tsc.c and
timer_cyclone.c, replacing it with the proper usage of jiffies.h.
Caught by gregkh.

into home.osdl.org:/home/torvalds/v2.5/linux

This patch corrects a trivial thinko in the manual resource api.

This patch updates the resource manager so that it actually assigns
disabled resources when they are requested by the device.

Some devices will allow for individual resources to be disabled,
even when the device as a whole is active.  The current PnP
resource manager is not handling this situation properly.  This
patch corrects the issue by detecting disabled resources and then
flagging them. The pnp layer will now skip over any disabled 
resources.  Interface updates have also been included so that we
can properly display resource tables when a resource is disabled.

Also note that a new flag "IORESOURCE_DISABLED" has been added to
linux/ioports.h.