[PATCH] docs cgroups: add another example size for hugetlb

[PATCH] docs cgroups: add another example size for hugetlb

[Odin Ugedal]

Add another example to clarify that HugePages smaller than 1MB will
be displayed using "KB", with an uppercased K (eg. 20KB), and not the
normal SI prefix kilo (small k).

Because of a misunderstanding/copy-paste error inside runc
(see https://github.com/opencontainers/runc/pull/2065), it tried
accessing the cgroup control file of a 64kB HugePage using
"hugetlb.64kB._____" instead of the correct "hugetlb.64KB._____".

Adding a new example will make it clear how sizes smaller than 1MB are
handled.

Signed-off-by: Odin Ugedal <odin@ugedal.com>
---
 Documentation/cgroup-v1/hugetlb.txt | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/Documentation/cgroup-v1/hugetlb.txt b/Documentation/cgroup-v1/hugetlb.txt
index 106245c3aecc..1260e5369b9b 100644
--- a/Documentation/cgroup-v1/hugetlb.txt
+++ b/Documentation/cgroup-v1/hugetlb.txt
@@ -32,14 +32,18 @@ Brief summary of control files
  hugetlb.<hugepagesize>.usage_in_bytes     # show current usage for "hugepagesize" hugetlb
  hugetlb.<hugepagesize>.failcnt		   # show the number of allocation failure due to HugeTLB limit
 
-For a system supporting two hugepage size (16M and 16G) the control
+For a system supporting three hugepage sizes (64k, 32M and 1G), the control
 files include:
 
-hugetlb.16GB.limit_in_bytes
-hugetlb.16GB.max_usage_in_bytes
-hugetlb.16GB.usage_in_bytes
-hugetlb.16GB.failcnt
-hugetlb.16MB.limit_in_bytes
-hugetlb.16MB.max_usage_in_bytes
-hugetlb.16MB.usage_in_bytes
-hugetlb.16MB.failcnt
+hugetlb.1GB.limit_in_bytes
+hugetlb.1GB.max_usage_in_bytes
+hugetlb.1GB.usage_in_bytes
+hugetlb.1GB.failcnt
+hugetlb.64KB.limit_in_bytes
+hugetlb.64KB.max_usage_in_bytes
+hugetlb.64KB.usage_in_bytes
+hugetlb.64KB.failcnt
+hugetlb.32MB.limit_in_bytes
+hugetlb.32MB.max_usage_in_bytes
+hugetlb.32MB.usage_in_bytes
+hugetlb.32MB.failcnt
-- 
2.21.0

Re: [PATCH] docs cgroups: add another example size for hugetlb

[Tejun Heo]

On Thu, May 30, 2019 at 12:24:25AM +0200, Odin Ugedal wrote:
> Add another example to clarify that HugePages smaller than 1MB will
> be displayed using "KB", with an uppercased K (eg. 20KB), and not the
> normal SI prefix kilo (small k).
> 
> Because of a misunderstanding/copy-paste error inside runc
> (see https://github.com/opencontainers/runc/pull/2065), it tried
> accessing the cgroup control file of a 64kB HugePage using
> "hugetlb.64kB._____" instead of the correct "hugetlb.64KB._____".
> 
> Adding a new example will make it clear how sizes smaller than 1MB are
> handled.
> 
> Signed-off-by: Odin Ugedal <odin@ugedal.com>

Applied to cgroup/for-5.2-fixes.

Thanks.

-- 
tejun