linux

iv/linux

Fork 0

Commit Graph

Author	SHA1	Message	Date
Peter Zijlstra	a42dde0415	mm: bdi: allow setting a maximum for the bdi dirty limit Add "max_ratio" to /sys/class/bdi. This indicates the maximum percentage of the global dirty threshold allocated to this bdi. [mszeredi@suse.cz] - fix parsing in max_ratio_store(). - export bdi_set_max_ratio() to modules - limit bdi_dirty with bdi->max_ratio - document new sysfs attribute Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2008-04-30 08:29:50 -07:00
Peter Zijlstra	f16b34aa13	lib: proportion: fix underflow in prop_norm_percpu() Zhe Jiang noticed that its possible to underflow pl->events in prop_norm_percpu() when the value returned by percpu_counter_read() is less than the error on that read and the period delay > 1. In that case half might not trigger the batch increment and the value will be identical on the next iteration, causing the same half to be subtracted again and again. Fix this by rewriting the division as a single subtraction instead of a subtraction loop and using percpu_counter_sum() when the value returned by percpu_counter_read() is smaller than the error. The latter is still needed if we want pl->events to shrink properly in the error region. [akpm@linux-foundation.org: cleanups] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Jiang Zhe <zhe.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2007-12-23 12:54:37 -08:00
Peter Zijlstra	145ca25eb2	lib: floating proportions Given a set of objects, floating proportions aims to efficiently give the proportional 'activity' of a single item as compared to the whole set. Where 'activity' is a measure of a temporal property of the items. It is efficient in that it need not inspect any other items of the set in order to provide the answer. It is not even needed to know how many other items there are. It has one parameter, and that is the period of 'time' over which the 'activity' is measured. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2007-10-17 08:42:45 -07:00

Author

SHA1

Message

Date

Peter Zijlstra

a42dde0415

mm: bdi: allow setting a maximum for the bdi dirty limit

Add "max_ratio" to /sys/class/bdi.  This indicates the maximum percentage of
the global dirty threshold allocated to this bdi.

[mszeredi@suse.cz]

 - fix parsing in max_ratio_store().
 - export bdi_set_max_ratio() to modules
 - limit bdi_dirty with bdi->max_ratio
 - document new sysfs attribute

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2008-04-30 08:29:50 -07:00

Peter Zijlstra

f16b34aa13

lib: proportion: fix underflow in prop_norm_percpu()

Zhe Jiang noticed that its possible to underflow pl->events in
prop_norm_percpu() when the value returned by percpu_counter_read() is less
than the error on that read and the period delay > 1.  In that case half might
not trigger the batch increment and the value will be identical on the next
iteration, causing the same half to be subtracted again and again.

Fix this by rewriting the division as a single subtraction instead of a
subtraction loop and using percpu_counter_sum() when the value returned by
percpu_counter_read() is smaller than the error.

The latter is still needed if we want pl->events to shrink properly in the
error region.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Jiang Zhe <zhe.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2007-12-23 12:54:37 -08:00

Peter Zijlstra

145ca25eb2

lib: floating proportions

Given a set of objects, floating proportions aims to efficiently give the
proportional 'activity' of a single item as compared to the whole set. Where
'activity' is a measure of a temporal property of the items.

It is efficient in that it need not inspect any other items of the set
in order to provide the answer. It is not even needed to know how many
other items there are.

It has one parameter, and that is the period of 'time' over which the
'activity' is measured.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2007-10-17 08:42:45 -07:00

3 Commits