On 29 Oct 2020, at 20:28, Andrew Morton wrote:
On Thu, 29 Oct 2020 17:31:28 -0400 Zi Yan ziy@nvidia.com wrote:
Shall you add Fixes tag to commit 1da2f328fa643bd72197dfed0c655148af31e4eb? And may cc stable.
Sure.
Fixes: 1da2f328fa64 (“mm,thp,compaction,cma: allow THP migration for CMA allocations”)
stable cc'ed.
A think a cc:stable really requires a description of the end-user visible effects of the bug. Could you please provide that?
Sure.
For example, in a system with 16GB memory and an 8GB CMA region reserved by hugetlb_cma, if we first allocate 10GB THPs and mlock them (so some THPs are allocated in the CMA region and mlocked), reserving 6 1GB hugetlb pages via /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages will get stuck (looping in too_many_isolated function) until we kill either task. With the patch applied, oom will kill the application with 10GB THPs and let hugetlb page reservation finish.
— Best Regards, Yan Zi