[PATCH 02/13] selftests/mm: fix hugetlb pathname construction in charge_reserved_hugetlb.sh

Sayali Patil posted 13 patches 4 weeks, 1 day ago
Only 12 patches received!
There is a newer version of this series
[PATCH 02/13] selftests/mm: fix hugetlb pathname construction in charge_reserved_hugetlb.sh
Posted by Sayali Patil 4 weeks, 1 day ago
The charge_reserved_hugetlb.sh script assumes hugetlb cgroup memory
interface file names use the "<size>MB" format
(e.g. hugetlb.1024MB.current).
This assumption breaks on systems with larger huge pages such as 1GB,
where the kernel exposes normalized units:
    hugetlb.1GB.current
    hugetlb.1GB.max
    hugetlb.1GB.rsvd.max
    ...

As a result, the script attempts to access files like
hugetlb.1024MB.current, which do not exist when the kernel reports the
size in GB.

Normalize the huge page size and construct the pathname using the
appropriate unit (MB or GB), matching the hugetlb controller naming.

Fixes: 209376ed2a84 ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
---
 .../selftests/mm/charge_reserved_hugetlb.sh   | 42 +++++++++++++------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
index c9fe68b6fcf9..6bec53e16e05 100755
--- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
@@ -89,6 +89,15 @@ function get_machine_hugepage_size() {
 }
 
 MB=$(get_machine_hugepage_size)
+if (( MB >= 1024 )); then
+        # For 1GB hugepages
+        UNIT="GB"
+        MB_DISPLAY=$((MB / 1024))
+else
+        # For 2MB hugepages
+        UNIT="MB"
+        MB_DISPLAY=$MB
+fi
 
 function setup_cgroup() {
   local name="$1"
@@ -98,11 +107,12 @@ function setup_cgroup() {
   mkdir $cgroup_path/$name
 
   echo writing cgroup limit: "$cgroup_limit"
-  echo "$cgroup_limit" >$cgroup_path/$name/hugetlb.${MB}MB.$fault_limit_file
+  echo "$cgroup_limit" > \
+	  $cgroup_path/$name/hugetlb.${MB_DISPLAY}${UNIT}.$fault_limit_file
 
   echo writing reservation limit: "$reservation_limit"
   echo "$reservation_limit" > \
-    $cgroup_path/$name/hugetlb.${MB}MB.$reservation_limit_file
+    $cgroup_path/$name/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_limit_file
 
   if [ -e "$cgroup_path/$name/cpuset.cpus" ]; then
     echo 0 >$cgroup_path/$name/cpuset.cpus
@@ -137,7 +147,7 @@ function wait_for_file_value() {
 
 function wait_for_hugetlb_memory_to_get_depleted() {
   local cgroup="$1"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file"
 
   wait_for_file_value "$path" "0"
 }
@@ -145,7 +155,7 @@ function wait_for_hugetlb_memory_to_get_depleted() {
 function wait_for_hugetlb_memory_to_get_reserved() {
   local cgroup="$1"
   local size="$2"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file"
 
   wait_for_file_value "$path" "$size"
 }
@@ -153,7 +163,7 @@ function wait_for_hugetlb_memory_to_get_reserved() {
 function wait_for_hugetlb_memory_to_get_written() {
   local cgroup="$1"
   local size="$2"
-  local path="$cgroup_path/$cgroup/hugetlb.${MB}MB.$fault_usage_file"
+  local path="$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file"
 
   wait_for_file_value "$path" "$size"
 }
@@ -175,8 +185,8 @@ function write_hugetlbfs_and_get_usage() {
   hugetlb_difference=0
   reserved_difference=0
 
-  local hugetlb_usage=$cgroup_path/$cgroup/hugetlb.${MB}MB.$fault_usage_file
-  local reserved_usage=$cgroup_path/$cgroup/hugetlb.${MB}MB.$reservation_usage_file
+  local hugetlb_usage=$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local reserved_usage=$cgroup_path/$cgroup/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
 
   local hugetlb_before=$(cat $hugetlb_usage)
   local reserved_before=$(cat $reserved_usage)
@@ -307,8 +317,10 @@ function run_test() {
 
   cleanup_hugetlb_memory "hugetlb_cgroup_test"
 
-  local final_hugetlb=$(cat $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB}MB.$fault_usage_file)
-  local final_reservation=$(cat $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB}MB.$reservation_usage_file)
+  local final_hugetlb=$(cat \
+	 $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file)
+  local final_reservation=$(cat \
+	  $cgroup_path/hugetlb_cgroup_test/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file)
 
   echo $hugetlb_difference
   echo $reserved_difference
@@ -364,10 +376,14 @@ function run_multiple_cgroup_test() {
   reservation_failed1=$reservation_failed
   oom_killed1=$oom_killed
 
-  local cgroup1_hugetlb_usage=$cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB}MB.$fault_usage_file
-  local cgroup1_reservation_usage=$cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB}MB.$reservation_usage_file
-  local cgroup2_hugetlb_usage=$cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB}MB.$fault_usage_file
-  local cgroup2_reservation_usage=$cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB}MB.$reservation_usage_file
+  local cgroup1_hugetlb_usage=\
+	  $cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local cgroup1_reservation_usage=\
+	  $cgroup_path/hugetlb_cgroup_test1/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
+  local cgroup2_hugetlb_usage=\
+	  $cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB_DISPLAY}${UNIT}.$fault_usage_file
+  local cgroup2_reservation_usage=\
+	  $cgroup_path/hugetlb_cgroup_test2/hugetlb.${MB_DISPLAY}${UNIT}.$reservation_usage_file
 
   local usage_before_second_write=$(cat $cgroup1_hugetlb_usage)
   local reservation_usage_before_second_write=$(cat $cgroup1_reservation_usage)
-- 
2.52.0
Re: [PATCH 02/13] selftests/mm: fix hugetlb pathname construction in charge_reserved_hugetlb.sh
Posted by Zi Yan 4 weeks, 1 day ago
On 10 Mar 2026, at 5:49, Sayali Patil wrote:

> The charge_reserved_hugetlb.sh script assumes hugetlb cgroup memory
> interface file names use the "<size>MB" format
> (e.g. hugetlb.1024MB.current).
> This assumption breaks on systems with larger huge pages such as 1GB,
> where the kernel exposes normalized units:
>     hugetlb.1GB.current
>     hugetlb.1GB.max
>     hugetlb.1GB.rsvd.max
>     ...
>
> As a result, the script attempts to access files like
> hugetlb.1024MB.current, which do not exist when the kernel reports the
> size in GB.
>
> Normalize the huge page size and construct the pathname using the
> appropriate unit (MB or GB), matching the hugetlb controller naming.
>
> Fixes: 209376ed2a84 ("selftests/vm: make charge_reserved_hugetlb.sh work with existing cgroup setting")
> Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
> Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
> ---
>  .../selftests/mm/charge_reserved_hugetlb.sh   | 42 +++++++++++++------
>  1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> index c9fe68b6fcf9..6bec53e16e05 100755
> --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> +++ b/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> @@ -89,6 +89,15 @@ function get_machine_hugepage_size() {
>  }
>
>  MB=$(get_machine_hugepage_size)
> +if (( MB >= 1024 )); then
> +        # For 1GB hugepages
> +        UNIT="GB"
> +        MB_DISPLAY=$((MB / 1024))
> +else
> +        # For 2MB hugepages
> +        UNIT="MB"
> +        MB_DISPLAY=$MB
> +fi
>
>  function setup_cgroup() {
>    local name="$1"
> @@ -98,11 +107,12 @@ function setup_cgroup() {
>    mkdir $cgroup_path/$name
>
>    echo writing cgroup limit: "$cgroup_limit"
> -  echo "$cgroup_limit" >$cgroup_path/$name/hugetlb.${MB}MB.$fault_limit_file
> +  echo "$cgroup_limit" > \
> +	  $cgroup_path/$name/hugetlb.${MB_DISPLAY}${UNIT}.$fault_limit_file

MB_DISPLAY and UNIT always show up together, maybe just use a single variable
instead. But feel free to ignore this. Anyway,

Reviewed-by: Zi Yan <ziy@nvidia.com>

Best Regards,
Yan, Zi