Merge branch 'from-linus' into upstream

S: United Kingdom

N: Luiz Fernando N. Capitulino

E: lcapitulino@terra.com.br

E: lcapitulino@prefeitura.sp.gov.br

W: http://www.telecentros.sp.gov.br

D: Little fixes and a lot of janitorial work

S: E-GOV Telecentros SP

E: lcapitulino@mandriva.com.br

E: lcapitulino@gmail.com

W: http://www.cpu.eti.br

D: misc kernel hacking

S: Mandriva

S: Brazil

N: Remy Card

always going to be SAC addressable.

The first thing your driver needs to do is query the PCI platform

layer with your devices DAC addressing capabilities:

layer if it is capable of handling your devices DAC addressing

capabilities:

	int pci_dac_set_dma_mask(struct pci_dev *pdev, u64 mask);

	int pci_dac_dma_supported(struct pci_dev *hwdev, u64 mask);

This routine behaves identically to pci_set_dma_mask.  You may not

use the following interfaces if this routine fails.

You may not use the following interfaces if this routine fails.

Next, DMA addresses using this API are kept track of using the

dma64_addr_t type.  It is guaranteed to be big enough to hold any

	+	spin_lock(&listmutex);

		list_for_each_entry(p, head, lp) {

			if (p->key == key) {

				list_del(&p->list);

	-			list_del(&p->list);

	-			write_unlock(&listmutex);

	+			list_del_rcu(&p->list);

	+			spin_unlock(&listmutex);

	+			synchronize_rcu();

				kfree(p);

 5   write_lock(&listmutex);            5   spin_lock(&listmutex);

 6   list_for_each_entry(p, head, lp) { 6   list_for_each_entry(p, head, lp) {

 7     if (p->key == key) {             7     if (p->key == key) {

 8       list_del(&p->list);            8       list_del(&p->list);

 8       list_del(&p->list);            8       list_del_rcu(&p->list);

 9       write_unlock(&listmutex);      9       spin_unlock(&listmutex);

                                       10       synchronize_rcu();

10       kfree(p);                     11       kfree(p);

Linux Kernel patch sumbittal checklist

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Here are some basic things that developers should do if they

want to see their kernel patch submittals accepted quicker.

Here are some basic things that developers should do if they want to see their

kernel patch submissions accepted more quickly.

These are all above and beyond the documentation that is provided

in Documentation/SubmittingPatches and elsewhere about submitting

Linux kernel patches.

These are all above and beyond the documentation that is provided in

Documentation/SubmittingPatches and elsewhere regarding submitting Linux

kernel patches.

- Builds cleanly with applicable or modified CONFIG options =y, =m, and =n.

  No gcc warnings/errors, no linker warnings/errors.

1: Builds cleanly with applicable or modified CONFIG options =y, =m, and

   =n.  No gcc warnings/errors, no linker warnings/errors.

- Passes allnoconfig, allmodconfig

2: Passes allnoconfig, allmodconfig

- Builds on multiple CPU arch-es by using local cross-compile tools

3: Builds on multiple CPU architectures by using local cross-compile tools

   or something like PLM at OSDL.

- ppc64 is a good architecture for cross-compilation checking because it

4: ppc64 is a good architecture for cross-compilation checking because it

   tends to use `unsigned long' for 64-bit quantities.

- Matches kernel coding style(!)

5: Matches kernel coding style(!)

- Any new or modified CONFIG options don't muck up the config menu.

6: Any new or modified CONFIG options don't muck up the config menu.

- All new Kconfig options have help text.

7: All new Kconfig options have help text.

- Has been carefully reviewed with respect to relevant Kconfig

  combinations.  This is very hard to get right with testing --

  brainpower pays off here.

8: Has been carefully reviewed with respect to relevant Kconfig

   combinations.  This is very hard to get right with testing -- brainpower

   pays off here.

- Check cleanly with sparse.

9: Check cleanly with sparse.

- Use 'make checkstack' and 'make namespacecheck' and fix any

  problems that they find.  Note:  checkstack does not point out

  problems explicitly, but any one function that uses more than

  512 bytes on the stack is a candidate for change.

10: Use 'make checkstack' and 'make namespacecheck' and fix any problems

    that they find.  Note: checkstack does not point out problems explicitly,

    but any one function that uses more than 512 bytes on the stack is a

    candidate for change.

- Include kernel-doc to document global kernel APIs.  (Not required

  for static functions, but OK there also.)  Use 'make htmldocs'

  or 'make mandocs' to check the kernel-doc and fix any issues.

11: Include kernel-doc to document global kernel APIs.  (Not required for

    static functions, but OK there also.) Use 'make htmldocs' or 'make

    mandocs' to check the kernel-doc and fix any issues.

- Has been tested with CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT,

12: Has been tested with CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT,

    CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES,

    CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEP all simultaneously

    enabled.

- Has been build- and runtime tested with and without CONFIG_SMP and

13: Has been build- and runtime tested with and without CONFIG_SMP and

    CONFIG_PREEMPT.

- If the patch affects IO/Disk, etc: has been tested with and without

14: If the patch affects IO/Disk, etc: has been tested with and without

    CONFIG_LBD.

15: All codepaths have been exercised with all lockdep features enabled.

2006-APR-27

16: All new /proc entries are documented under Documentation/

17: All new kernel boot parameters are documented in

    Documentation/kernel-parameters.txt.

18: All new module parameters are documented with MODULE_PARM_DESC()

Delay accounting

----------------

Tasks encounter delays in execution when they wait

for some kernel resource to become available e.g. a

runnable task may wait for a free CPU to run on.

The per-task delay accounting functionality measures

the delays experienced by a task while

a) waiting for a CPU (while being runnable)

b) completion of synchronous block I/O initiated by the task

c) swapping in pages

and makes these statistics available to userspace through

the taskstats interface.

Such delays provide feedback for setting a task's cpu priority,

io priority and rss limit values appropriately. Long delays for

important tasks could be a trigger for raising its corresponding priority.

The functionality, through its use of the taskstats interface, also provides

delay statistics aggregated for all tasks (or threads) belonging to a

thread group (corresponding to a traditional Unix process). This is a commonly

needed aggregation that is more efficiently done by the kernel.

Userspace utilities, particularly resource management applications, can also

aggregate delay statistics into arbitrary groups. To enable this, delay

statistics of a task are available both during its lifetime as well as on its

exit, ensuring continuous and complete monitoring can be done.

Interface

---------

Delay accounting uses the taskstats interface which is described

in detail in a separate document in this directory. Taskstats returns a

generic data structure to userspace corresponding to per-pid and per-tgid

statistics. The delay accounting functionality populates specific fields of

this structure. See

     include/linux/taskstats.h

for a description of the fields pertaining to delay accounting.

It will generally be in the form of counters returning the cumulative

delay seen for cpu, sync block I/O, swapin etc.

Taking the difference of two successive readings of a given

counter (say cpu_delay_total) for a task will give the delay

experienced by the task waiting for the corresponding resource

in that interval.

When a task exits, records containing the per-task statistics

are sent to userspace without requiring a command. If it is the last exiting

task of a thread group, the per-tgid statistics are also sent. More details

are given in the taskstats interface description.

The getdelays.c userspace utility in this directory allows simple commands to

be run and the corresponding delay statistics to be displayed. It also serves

as an example of using the taskstats interface.

Usage

-----

Compile the kernel with

	CONFIG_TASK_DELAY_ACCT=y

	CONFIG_TASKSTATS=y

Enable the accounting at boot time by adding

the following to the kernel boot options

	delayacct

and after the system has booted up, use a utility

similar to  getdelays.c to access the delays

seen by a given task or a task group (tgid).

The utility also allows a given command to be

executed and the corresponding delays to be

seen.

General format of the getdelays command

getdelays [-t tgid] [-p pid] [-c cmd...]

Get delays, since system boot, for pid 10

# ./getdelays -p 10

(output similar to next case)

Get sum of delays, since system boot, for all pids with tgid 5

# ./getdelays -t 5

CPU	count	real total	virtual total	delay total

	7876	92005750	100000000	24001500

IO	count	delay total

	0	0

MEM	count	delay total

	0	0

Get delays seen in executing a given simple command

# ./getdelays -c ls /

bin   data1  data3  data5  dev  home  media  opt   root  srv        sys  usr

boot  data2  data4  data6  etc  lib   mnt    proc  sbin  subdomain  tmp  var

CPU	count	real total	virtual total	delay total

	6	4000250		4000000		0

IO	count	delay total

	0	0

MEM	count	delay total

	0	0