Feng Tang d2226ebd54 mm/hugetlb: add dedicated func to get 'allowed' nodemask for current process ... Muchun Song found that after MPOL_PREFERRED_MANY policy was introduced in commit b27abaccf8 ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes"), the policy_nodemask_current()'s semantics for this new policy has been changed, which returns 'preferred' nodes instead of 'allowed' nodes. With the changed semantic of policy_nodemask_current, a task with MPOL_PREFERRED_MANY policy could fail to get its reservation even though it can fall back to other nodes (either defined by cpusets or all online nodes) for that reservation failing mmap calles unnecessarily early. The fix is to not consider MPOL_PREFERRED_MANY for reservations at all because they, unlike MPOL_MBIND, do not pose any actual hard constrain. Michal suggested the policy_nodemask_current() is only used by hugetlb, and could be moved to hugetlb code with more explicit name to enforce the 'allowed' semantics for which only MPOL_BIND policy matters. apply_policy_zone() is made extern to be called in hugetlb code and its return value is changed to bool. [1]. https://lore.kernel.org/lkml/20220801084207.39086-1-songmuchun@bytedance.com/t/ Link: https://lkml.kernel.org/r/20220805005903.95563-1-feng.tang@intel.com Fixes: b27abaccf8 ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes") Signed-off-by: Feng Tang <feng.tang@intel.com> Reported-by: Muchun Song <songmuchun@bytedance.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ben Widawsky <bwidawsk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2022-09-11 20:25:50 -07:00
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acpi	Merge branch 'acpi-properties'	2022-08-11 19:21:03 +02:00
asm-generic	Seventeen hotfixes. Mostly memory management things. Ten patches are	2022-08-28 14:49:59 -07:00
clocksource
crypto	for-5.20/block-2022-08-04	2022-08-04 20:00:14 -07:00
drm
dt-bindings	power supply and reset changes for the v6.0 series	2022-08-12 09:37:33 -07:00
keys
kunit
kvm
linux	mm/hugetlb: add dedicated func to get 'allowed' nodemask for current process	2022-09-11 20:25:50 -07:00
math-emu
media	SPDX changes for 6.0-rc1	2022-08-04 12:12:54 -07:00
memory
misc
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf	2022-08-24 19:18:10 -07:00
pcmcia
ras	mm, hwpoison: enable memory error handling on 1GB hugepage	2022-08-08 18:06:44 -07:00
rdma	dma-mapping updates	2022-08-06 10:56:45 -07:00
rv
scsi	SCSI misc on 20220813	2022-08-13 13:41:48 -07:00
soc	net: mscc: ocelot: keep ocelot_stat_layout by reg address, not offset	2022-08-17 21:58:32 -07:00
sound
target
trace	mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage	2022-09-11 20:25:46 -07:00
uapi	userfaultfd: add /dev/userfaultfd for fine grained access control	2022-09-11 20:25:48 -07:00
ufs	scsi: ufs: core: Enable link lost interrupt	2022-08-11 22:04:32 -04:00
vdso
video
xen	x86/xen: Add support for HVMOP_set_evtchn_upcall_vector	2022-08-12 11:28:21 +02:00