| Message ID | 20230314042351.13134-4-chaitanyas.prakash@arm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d6c2789778c59c1768567099eb2fdd32d790c38a |
| Headers | show |
| Series | selftests: Fix virtual address range for arm64 | expand |
On 14.03.23 05:23, Chaitanya S Prakash wrote: > 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. Which tests in particular require that? Subjects should start with "selftests/mm" instead of more generic "selftests:"
On 3/16/23 21:01, David Hildenbrand wrote: > On 14.03.23 05:23, Chaitanya S Prakash wrote: >> 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. > > Which tests in particular require that? This is applicable to the virtual address range selftest. > > Subjects should start with "selftests/mm" instead of more generic > "selftests:" I'll make the necessary changes. >
diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 8984e0bb58c7..c0f93b668c0c 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
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. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-mm@kvack.org Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com> --- tools/testing/selftests/mm/run_vmtests.sh | 8 ++++++++ 1 file changed, 8 insertions(+)