Baolin Wang 7962e05a83 selftests: khugepaged: fix the shmem collapse failure ... When running the khugepaged selftest for shmem (./khugepaged all:shmem), I encountered the following test failures: : Run test: collapse_full (khugepaged:shmem) : Collapse multiple fully populated PTE table.... Fail : ... : Run test: collapse_single_pte_entry (khugepaged:shmem) : Collapse PTE table with single PTE entry present.... Fail : ... : Run test: collapse_full_of_compound (khugepaged:shmem) : Allocate huge page... OK : Split huge page leaving single PTE page table full of compound pages... OK : Collapse PTE table full of compound pages.... Fail The reason for the failure is that it will set MADV_NOHUGEPAGE to prevent khugepaged from continuing to scan shmem VMA after khugepaged finishes scanning in the wait_for_scan() function. Moreover, shmem requires a refault to establish PMD mappings. However, after commit 2b0f922323 ("mm: don't install PMD mappings when THPs are disabled by the hw/process/vma"), PMD mappings are prevented if the VMA is set with MADV_NOHUGEPAGE flag, so shmem cannot establish PMD mappings during refault. One way to fix this issue is to move the MADV_NOHUGEPAGE setting after the shmem refault. After shmem refault and check huge, the test case will unmap the shmem immediately. So it seems unnecessary to set the MADV_NOHUGEPAGE. Then we can simply drop the MADV_NOHUGEPAGE setting, and all khugepaged test cases passed. Link: https://lkml.kernel.org/r/d8502fc50d0304c2afd27ced062b1d636b7a872e.1749779183.git.baolin.wang@linux.alibaba.com Fixes: 2b0f922323 ("mm: don't install PMD mappings when THPs are disabled by the hw/process/vma") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Tested-by: Dev Jain <dev.jain@arm.com> Tested-by: Mario Casquero <mcasquer@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2025-07-09 22:42:09 -07:00
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accounting
arch	LoongArch: Replace __ASSEMBLY__ with __ASSEMBLER__ in headers	2025-06-26 20:07:10 +08:00
bootconfig	tools/bootconfig: specify LDFLAGS as an argument to CC	2025-05-16 11:22:54 +09:00
bpf	tools/resolve_btfids: Fix build when cross compiling kernel with clang.	2025-06-10 09:09:27 -07:00
build
certs
cgroup
counter
crypto
debugging
firewire
firmware
gpio
hv	tools: hv: Enable debug logs for hv_kvp_daemon	2025-05-23 16:30:55 +00:00
iio	iio: normalize array sentinel style	2025-04-22 19:10:04 +01:00
include	tools headers: Synchronize linux/bits.h with the kernel sources	2025-06-17 16:55:24 -03:00
kvm/kvm_stat
laptop
leds
lib	libbpf: Fix possible use-after-free for externs	2025-06-25 12:28:58 -07:00
memory-model	tools/memory-model/Documentation: Fix SRCU section in explanation.txt	2025-04-23 12:17:04 -07:00
mm	tools/mm: add script to display page state for a given PID and VADDR	2025-07-09 22:41:53 -07:00
net	tools: ynl: fix mixing ops and notifications on one socket	2025-06-19 08:37:39 -07:00
objtool	objtool: Add missing endian conversion to read_annotate()	2025-07-01 15:02:04 +02:00
pcmcia
perf	perf bench futex: Fix prctl include in musl libc	2025-06-17 18:29:42 -03:00
power	cpupower: split unitdir from libdir in Makefile	2025-06-09 10:17:46 -06:00
rcu
sched_ext
scripts
sound
spi
testing	selftests: khugepaged: fix the shmem collapse failure	2025-07-09 22:42:09 -07:00
thermal
time
tracing	tracing tools updates for v6.16:	2025-05-29 20:59:52 -07:00
usb
verification
virtio
wmi
workqueue
writeback
Makefile	tools/Makefile: Add ynl target	2025-04-28 17:18:48 -07:00