linux-toradex.git/Documentation/cgroups, branch tegra

cgroup: Add generic cgroup subsystem permission checks

2011-12-01T05:38:49+00:00

Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'allow_attach' handler, then we fall back to doing our checks
the old way.

Use the 'allow_attach' handler for the 'cpu' cgroup to allow
non-root processes to add arbitrary processes to a 'cpu' cgroup
if it has the CAP_SYS_NICE capability set.

This version of the patch adds a 'allow_attach' handler instead
of reusing the 'can_attach' handler.  If the 'can_attach' handler
is reused, a new cgroup that implements 'can_attach' but not
the permission checks could end up with no permission checks
at all.

Change-Id: Icfa950aa9321d1ceba362061d32dc7dfa2c64f0c
Original-Author: San Mehat 
Signed-off-by: Colin Cross

scheduler: cpuacct: Enable platform callbacks for cpuacct power tracking

2011-12-01T05:38:19+00:00

Platform must register cpu power function that return power in
milliWatt seconds.

Change-Id: I1caa0335e316c352eee3b1ddf326fcd4942bcbe8
Signed-off-by: Mike Chan

scheduler: cpuacct: Enable platform hooks to track cpuusage for CPU frequencies

2011-12-01T05:38:19+00:00

Introduce new platform callback hooks for cpuacct for tracking CPU frequencies

Not all platforms / architectures have a set CPU_FREQ_TABLE defined
for CPU transition speeds. In order to track time spent in at various
CPU frequencies, we enable platform callbacks from cpuacct for this accounting.

Architectures that support overclock boosting, or don't have pre-defined
frequency tables can implement their own bucketing system that makes sense
given their cpufreq scaling abilities.

New file:
cpuacct.cpufreq reports the CPU time (in nanoseconds) spent at each CPU
frequency.

Change-Id: I10a80b3162e6fff3a8a2f74dd6bb37e88b12ba96
Signed-off-by: Mike Chan

memcg: Revert "memcg: add memory.vmscan_stat"

2011-09-15T01:09:38+00:00

Revert the post-3.0 commit 82f9d486e59f5 ("memcg: add
memory.vmscan_stat").

The implementation of per-memcg reclaim statistics violates how memcg
hierarchies usually behave: hierarchically.

The reclaim statistics are accounted to child memcgs and the parent
hitting the limit, but not to hierarchy levels in between.  Usually,
hierarchical statistics are perfectly recursive, with each level
representing the sum of itself and all its children.

Since this exports statistics to userspace, this may lead to confusion
and problems with changing things after the release, so revert it now,
we can try again later.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Michal Hocko 
Cc: Ying Han 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: add memory.vmscan_stat

2011-07-26T23:49:42+00:00

The commit log of 0ae5e89c60c9 ("memcg: count the soft_limit reclaim
in...") says it adds scanning stats to memory.stat file.  But it doesn't
because we considered we needed to make a concensus for such new APIs.

This patch is a trial to add memory.scan_stat. This shows
  - the number of scanned pages(total, anon, file)
  - the number of rotated pages(total, anon, file)
  - the number of freed pages(total, anon, file)
  - the number of elaplsed time (including sleep/pause time)

  for both of direct/soft reclaim.

The biggest difference with oringinal Ying's one is that this file
can be reset by some write, as

  # echo 0 ...../memory.scan_stat

Example of output is here. This is a result after make -j 6 kernel
under 300M limit.

  [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.scan_stat
  [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.vmscan_stat
  scanned_pages_by_limit 9471864
  scanned_anon_pages_by_limit 6640629
  scanned_file_pages_by_limit 2831235
  rotated_pages_by_limit 4243974
  rotated_anon_pages_by_limit 3971968
  rotated_file_pages_by_limit 272006
  freed_pages_by_limit 2318492
  freed_anon_pages_by_limit 962052
  freed_file_pages_by_limit 1356440
  elapsed_ns_by_limit 351386416101
  scanned_pages_by_system 0
  scanned_anon_pages_by_system 0
  scanned_file_pages_by_system 0
  rotated_pages_by_system 0
  rotated_anon_pages_by_system 0
  rotated_file_pages_by_system 0
  freed_pages_by_system 0
  freed_anon_pages_by_system 0
  freed_file_pages_by_system 0
  elapsed_ns_by_system 0
  scanned_pages_by_limit_under_hierarchy 9471864
  scanned_anon_pages_by_limit_under_hierarchy 6640629
  scanned_file_pages_by_limit_under_hierarchy 2831235
  rotated_pages_by_limit_under_hierarchy 4243974
  rotated_anon_pages_by_limit_under_hierarchy 3971968
  rotated_file_pages_by_limit_under_hierarchy 272006
  freed_pages_by_limit_under_hierarchy 2318492
  freed_anon_pages_by_limit_under_hierarchy 962052
  freed_file_pages_by_limit_under_hierarchy 1356440
  elapsed_ns_by_limit_under_hierarchy 351386416101
  scanned_pages_by_system_under_hierarchy 0
  scanned_anon_pages_by_system_under_hierarchy 0
  scanned_file_pages_by_system_under_hierarchy 0
  rotated_pages_by_system_under_hierarchy 0
  rotated_anon_pages_by_system_under_hierarchy 0
  rotated_file_pages_by_system_under_hierarchy 0
  freed_pages_by_system_under_hierarchy 0
  freed_anon_pages_by_system_under_hierarchy 0
  freed_file_pages_by_system_under_hierarchy 0
  elapsed_ns_by_system_under_hierarchy 0

total_xxxx is for hierarchy management.

This will be useful for further memcg developments and need to be
developped before we do some complicated rework on LRU/softlimit
management.

This patch adds a new struct memcg_scanrecord into scan_control struct.
sc->nr_scanned at el is not designed for exporting information.  For
example, nr_scanned is reset frequentrly and incremented +2 at scanning
mapped pages.

To avoid complexity, I added a new param in scan_control which is for
exporting scanning score.

Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Michal Hocko 
Cc: Ying Han 
Cc: Andrew Bresticker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation: fix ambigous text for root cpuset

2011-07-23T17:58:08+00:00

Only the root cpuset has cpuset.memory_pressure_enabled flag,
but not the only one.

Signed-off-by: Wanlong Gao 
Signed-off-by: Randy Dunlap 
Acked-by: Paul Menage 
Signed-off-by: Linus Torvalds

Documentation: fix echo command in cgroups/cpuacct.txt

2011-07-23T17:58:08+00:00

Must echo a task id to the cgroups' tasks file, but not to a directory.

Signed-off-by: Wanlong Gao 
Acked-by: Paul Menage 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Documentation: fix cgroup blkio throttle filenames

2011-07-06T20:17:51+00:00

All the blkio.throttle.* file names are incorrectly reported without
".throttle" in the documentation. Fix it.

Signed-off-by: Andrea Righi 
Signed-off-by: Randy Dunlap 
Acked-by: Vivek Goyal 
Signed-off-by: Linus Torvalds

Documentation: fix cgroup typos and formatting

2011-06-16T04:52:50+00:00

Fix format and spelling.

Signed-off-by: Jörg Sommer 
Acked-by: Paul Menage 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Documentation: update cgroupfs mount point

2011-06-16T04:52:50+00:00

According to commit 676db4af0430 ("cgroupfs: create /sys/fs/cgroup to
mount cgroupfs on") the canonical mountpoint for the cgroup filesystem
is /sys/fs/cgroup.  Hence, this should be used in the documentation.

Signed-off-by: Jörg Sommer 
Acked-by: Paul Menage 
Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds