Re: [PATCH 3/3] hugetlbfs: don't retry when pool page allocations start to fail

[Vlastimil Babka]

On 8/3/19 12:39 AM, Mike Kravetz wrote:
> When allocating hugetlbfs pool pages via /proc/sys/vm/nr_hugepages,
> the pages will be interleaved between all nodes of the system.  If
> nodes are not equal, it is quite possible for one node to fill up
> before the others.  When this happens, the code still attempts to
> allocate pages from the full node.  This results in calls to direct
> reclaim and compaction which slow things down considerably.
> 
> When allocating pool pages, note the state of the previous allocation
> for each node.  If previous allocation failed, do not use the
> aggressive retry algorithm on successive attempts.  The allocation
> will still succeed if there is memory available, but it will not try
> as hard to free up memory.
> 
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Looks like only part of the (agreed with) suggestions were implemented?
- set_max_huge_pages() returns -ENOMEM if nodemask can't be allocated,
but hugetlb_hstate_alloc_pages() doesn't.
- there's still __GFP_NORETRY in nodemask allocations
- (cosmetics) Mel pointed out that NODEMASK_FREE() works fine with NULL
pointers

Thanks,
Vlastimil