From: Chaitanya S Prakash Date: Thu, 23 Mar 2023 06:01:21 +0000 (+0530) Subject: selftests/mm: set overcommit_policy as OVERCOMMIT_ALWAYS X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d6c2789778c59c1768567099eb2fdd32d790c38a;p=linux.git selftests/mm: set overcommit_policy as OVERCOMMIT_ALWAYS The kernel's default behaviour is to obstruct the allocation of high virtual address as it handles memory overcommit in a heuristic manner. Setting the parameter as OVERCOMMIT_ALWAYS, ensures kernel isn't susceptible to the availability of a platform's physical memory when denying a memory allocation request. Link: https://lkml.kernel.org/r/20230323060121.1175830-4-chaitanyas.prakash@arm.com Signed-off-by: Chaitanya S Prakash Cc: David Hildenbrand Cc: Shuah Khan Signed-off-by: Andrew Morton --- diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 8984e0bb58c7a..c0f93b668c0c7 100644 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -220,7 +220,15 @@ CATEGORY="mremap" run_test ./mremap_test CATEGORY="hugetlb" run_test ./thuge-gen if [ $VADDR64 -ne 0 ]; then + + # set overcommit_policy as OVERCOMMIT_ALWAYS so that kernel + # allows high virtual address allocation requests independent + # of platform's physical memory. + + prev_policy=$(cat /proc/sys/vm/overcommit_memory) + echo 1 > /proc/sys/vm/overcommit_memory CATEGORY="hugevm" run_test ./virtual_address_range + echo $prev_policy > /proc/sys/vm/overcommit_memory # virtual address 128TB switch test CATEGORY="hugevm" run_test ./va_128TBswitch.sh