Re: [PATCH v6 6/6] mm/page_isolation: remove migratetype parameter from more functions.

[Zi Yan <ziy@nvidia.com>]

On 30 May 2025, at 13:15, Vlastimil Babka wrote:

> On 5/30/25 18:22, Zi Yan wrote:
>> migratetype is no longer overwritten during pageblock isolation,
>> start_isolate_page_range(), has_unmovable_pages(), and
>> set_migratetype_isolate() no longer need which migratetype to restore
>> during isolation failure.
>>
>> For has_unmoable_pages(), it needs to know if the isolation is for CMA
>> allocation, so adding CMA_ALLOCATION to provide the information. At the
>> same time change isolation flags to enum pb_isolate_mode
>> (PB_ISOLATE_MODE_MEM_OFFLINE, PB_ISOLATE_MODE_CMA_ALLOC,
>> PB_ISOLATE_MODE_OTHER). Remove REPORT_FAILURE and check
>> MEMORY_OFFLINE instead, since only PB_ISOLATE_MODE_MEM_OFFLINE reports
>> isolation failures.
>>
>> alloc_contig_range() no longer needs migratetype. Replace it with
>> enum acr_flags_t to tell if an allocation is for CMA. So does
>> __alloc_contig_migrate_range().
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
>
>> ---
>>  drivers/virtio/virtio_mem.c    |  2 +-
>>  include/linux/gfp.h            |  9 ++++-
>>  include/linux/page-isolation.h | 20 ++++++++--
>>  include/trace/events/kmem.h    | 14 ++++---
>>  mm/cma.c                       |  2 +-
>>  mm/memory_hotplug.c            |  6 +--
>>  mm/page_alloc.c                | 27 ++++++-------
>>  mm/page_isolation.c            | 70 +++++++++++++++-------------------
>>  8 files changed, 82 insertions(+), 68 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>> index 56d0dbe62163..6bce70b139b2 100644
>> --- a/drivers/virtio/virtio_mem.c
>> +++ b/drivers/virtio/virtio_mem.c
>> @@ -1243,7 +1243,7 @@ static int virtio_mem_fake_offline(struct virtio_mem *vm, unsigned long pfn,
>>  		if (atomic_read(&vm->config_changed))
>>  			return -EAGAIN;
>>
>> -		rc = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE,
>> +		rc = alloc_contig_range(pfn, pfn + nr_pages, ACR_OTHER,
>>  					GFP_KERNEL);
>>  		if (rc == -ENOMEM)
>>  			/* whoops, out of memory */
>> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
>> index be160e8d8bcb..51990d571e3e 100644
>> --- a/include/linux/gfp.h
>> +++ b/include/linux/gfp.h
>> @@ -423,9 +423,16 @@ static inline bool gfp_compaction_allowed(gfp_t gfp_mask)
>>  extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma);
>>
>>  #ifdef CONFIG_CONTIG_ALLOC
>> +
>> +enum acr_flags_t {
>> +	ACR_CMA,	// CMA allocation
>> +	ACR_OTHER,	// other allocation
>> +};
>> +
>>  /* The below functions must be run on a range from a single zone. */
>>  extern int alloc_contig_range_noprof(unsigned long start, unsigned long end,
>> -			      unsigned migratetype, gfp_t gfp_mask);
>> +				     enum acr_flags_t alloc_flags,
>> +				     gfp_t gfp_mask);
>
> Nit: when used this way I think it's also rather a "mode" than "flags". It's
> probably sufficient though, I don't expect we'll be adding more and want to
> combine them in a flags way. So it's just about the enum's name.
>

So enum acr_flags_t to enum acr_mode_t? Sure. Let me send a fixup.

Best Regards,
Yan, Zi