On Tue 30-01-18 08:37:14, Anshuman Khandual wrote:
> alloc_contig_range() initiates compaction and eventual migration for
> the purpose of either CMA or HugeTLB allocation. At present, reason
> code remains the same MR_CMA for either of those cases. Lets add a
> new reason code which will differentiate the purpose of migration
> as HugeTLB allocation instead.
Why do we need it?
> Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
> ---
> include/linux/migrate.h | 1 +
> include/trace/events/migrate.h | 3 ++-
> mm/page_alloc.c | 14 ++++++++++----
> 3 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/migrate.h b/include/linux/migrate.h
> index a732598fcf83..44381c33a2bd 100644
> --- a/include/linux/migrate.h
> +++ b/include/linux/migrate.h
> @@ -26,6 +26,7 @@ enum migrate_reason {
> MR_MEMPOLICY_MBIND,
> MR_NUMA_MISPLACED,
> MR_CMA,
> + MR_HUGETLB,
> MR_TYPES
> };
>
> diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
> index bcf4daccd6be..61474c93f8f3 100644
> --- a/include/trace/events/migrate.h
> +++ b/include/trace/events/migrate.h
> @@ -20,7 +20,8 @@
> EM( MR_SYSCALL, "syscall_or_cpuset") \
> EM( MR_MEMPOLICY_MBIND, "mempolicy_mbind") \
> EM( MR_NUMA_MISPLACED, "numa_misplaced") \
> - EMe(MR_CMA, "cma")
> + EM( MR_CMA, "cma") \
> + EMe(MR_HUGETLB, "hugetlb")
>
> /*
> * First define the enums in the above macros to be exported to userspace
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 242565855d05..ce8a2f2d4994 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7588,13 +7588,14 @@ static unsigned long pfn_max_align_up(unsigned long
> pfn)
>
> /* [start, end) must belong to a single zone. */
> static int __alloc_contig_migrate_range(struct compact_control *cc,
> - unsigned long start, unsigned long end)
> + unsigned long start, unsigned long end,
> + unsigned migratetype)
> {
> /* This function is based on compact_zone() from compaction.c. */
> unsigned long nr_reclaimed;
> unsigned long pfn = start;
> unsigned int tries = 0;
> - int ret = 0;
> + int ret = 0, migrate_reason = 0;
>
> migrate_prep();
>
> @@ -7621,8 +7622,13 @@ static int __alloc_contig_migrate_range(struct
> compact_control *cc,
> &cc->migratepages);
> cc->nr_migratepages -= nr_reclaimed;
>
> + if (migratetype == MIGRATE_CMA)
> + migrate_reason = MR_CMA;
> + else
> + migrate_reason = MR_HUGETLB;
> +
> ret = migrate_pages(&cc->migratepages, new_page_alloc_contig,
> - NULL, 0, cc->mode, MR_CMA);
> + NULL, 0, cc->mode, migrate_reason);
> }
> if (ret < 0) {
> putback_movable_pages(&cc->migratepages);
> @@ -7710,7 +7716,7 @@ int alloc_contig_range(unsigned long start, unsigned
> long end,
> * allocated. So, if we fall through be sure to clear ret so that
> * -EBUSY is not accidentally used or returned to caller.
> */
> - ret = __alloc_contig_migrate_range(&cc, start, end);
> + ret = __alloc_contig_migrate_range(&cc, start, end, migratetype);
> if (ret && ret != -EBUSY)
> goto done;
> ret =0;
> --
> 2.11.0
>
--
Michal Hocko
SUSE Labs
