The patch titled Subject: selftests: set overcommit_policy as OVERCOMMIT_ALWAYS has been added to the -mm mm-unstable branch. Its filename is selftests-set-overcommit_policy-as-overcommit_always.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-set-overcommit_policy-as-overcommit_always.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Chaitanya S Prakash <chaitanyas.prakash@xxxxxxx> Subject: selftests: set overcommit_policy as OVERCOMMIT_ALWAYS Date: Tue, 14 Mar 2023 09:53:51 +0530 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/20230314042351.13134-4-chaitanyas.prakash@xxxxxxx Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@xxxxxxx> Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/tools/testing/selftests/mm/run_vmtests.sh~selftests-set-overcommit_policy-as-overcommit_always +++ a/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 _ Patches currently in -mm which might be from chaitanyas.prakash@xxxxxxx are selftests-change-map_chunk_size.patch selftests-change-nr_chunks_high-for-aarch64.patch selftests-set-overcommit_policy-as-overcommit_always.patch