linux.git/mm/pdflush.c, branch master

writeback: get rid of pdflush completely

2009-09-11T07:20:25+00:00

It is now unused, so kill it off.

Signed-off-by: Jens Axboe

Revert "mm: add /proc controls for pdflush threads"

2009-05-15T09:32:24+00:00

This reverts commit fafd688e4c0c34da0f3de909881117d374e4c7af.

Work is progressing to switch away from pdflush as the process backing
for flushing out dirty data. So it seems pointless to add more knobs
to control pdflush threads. The original author of the patch did not
have any specific use cases for adding the knobs, so we can easily
revert this before 2.6.30 to avoid having to maintain this API
forever.

Signed-off-by: Jens Axboe

mm: add /proc controls for pdflush threads

2009-04-07T15:31:03+00:00

Add /proc entries to give the admin the ability to control the minimum and
maximum number of pdflush threads.  This allows finer control of pdflush
on both large and small machines.

The rationale is simply one size does not fit all.  Admins on large and/or
small systems may want to tune the min/max pdflush thread count to best
suit their needs.  Right now the min/max is hardcoded to 2/8.  While
probably a fair estimate for smaller machines, large machines with large
numbers of CPUs and large numbers of filesystems/block devices may benefit
from larger numbers of threads working on different block devices.

Even if the background flushing algorithm is radically changed, it is
still likely that multiple threads will be involved and admins would still
desire finer control on the min/max other than to have to recompile the
kernel.

The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and
'/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions.

The minimum value for nr_pdflush_threads_min is 1 and the maximum value is
the current value of nr_pdflush_threads_max.  This minimum is required
since additional thread creation is performed in a pdflush thread itself.

The minimum value for nr_pdflush_threads_max is the current value of
nr_pdflush_threads_min and the maximum value can be 1000.

Documentation/sysctl/vm.txt is also updated.

[akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly]
Signed-off-by: Peter W Morreale 
Reviewed-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix pdflush thread creation upper bound

2009-04-07T15:31:03+00:00

Fix a race on creating pdflush threads.  Without the patch, it is possible
to create more than MAX_PDFLUSH_THREADS threads, and this has been
observed in practice on IO loaded SMP machines.

The fix involves moving the lock around to protect the check against the
thread count and correctly dealing with thread creation failure.

This fix also _mostly_ repairs a race condition on how quickly the threads
are created.  The original intent was to create a pdflush thread (up to
the max allowed) every second.  Without this patch is is possible to
create NCPUS pdflush threads concurrently.  The 'mostly' caveat is because
an assumption is made that thread creation will be successful.  If we fail
to create the thread, the miss is not considered fatal.  (we will try
again in 1 second)

Signed-off-by: Peter W Morreale 
Reviewed-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL

2009-03-30T11:35:11+00:00

Impact: cleanup

(Thanks to Al Viro for reminding me of this, via Ingo)

CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:

	#define CPU_MASK_ALL (cpumask_t) { { ... } }

Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:

	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)

Which formalizes this practice.  One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).

So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *).

Signed-off-by: Rusty Russell 
Acked-by: Ingo Molnar 
Reported-by: Al Viro 
Cc: Mike Travis

cpumask: convert mm/

2008-12-31T23:42:29+00:00

Impact: Use new API

Convert kernel mm functions to use struct cpumask.

We skip include/linux/percpu.h and mm/allocpercpu.c, which are in flux.

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Reviewed-by: Christoph Lameter

Remove Andrew Morton's old email accounts

2008-10-16T18:21:32+00:00

People can use the real name an an index into MAINTAINERS to find the
current email address.

Signed-off-by: Francois Cami 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pdflush: use time_after() instead of open-coding it

2008-07-25T17:53:28+00:00

Signed-off-by: OGAWA Hirofumi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/pdflush.c: merge the same code in two path

2008-05-13T15:02:24+00:00

Signed-off-by: Denis Cheng 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial

2008-04-21T23:36:46+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial: (24 commits)
  DOC:  A couple corrections and clarifications in USB doc.
  Generate a slightly more informative error msg for bad HZ
  fix typo "is" -> "if" in Makefile
  ext*: spelling fix prefered -> preferred
  DOCUMENTATION:  Use newer DEFINE_SPINLOCK macro in docs.
  KEYS:  Fix the comment to match the file name in rxrpc-type.h.
  RAID: remove trailing space from printk line
  DMA engine: typo fixes
  Remove unused MAX_NODES_SHIFT
  MAINTAINERS: Clarify access to OCFS2 development mailing list.
  V4L: Storage class should be before const qualifier (sn9c102)
  V4L: Storage class should be before const qualifier
  sonypi: Storage class should be before const qualifier
  intel_menlow: Storage class should be before const qualifier
  DVB: Storage class should be before const qualifier
  arm: Storage class should be before const qualifier
  ALSA: Storage class should be before const qualifier
  acpi: Storage class should be before const qualifier
  firmware_sample_driver.c: fix coding style
  MAINTAINERS: Add ati_remote2 driver
  ...

Fixed up trivial conflicts in firmware_sample_driver.c