On Sat, 2 Nov 2024 20:16:21 +0000 Qiang Liu <liuq131@xxxxxxxxxxxxxxx> wrote: > If the last cycle reads bogus compound_order() and blockpfn > end_pfn occurs, > it is possible that total_isolated will be less than nr_scanned. In this case, > strict mode should return 0, but the “if (strict && blockpfn < end_pfn)” > statement cannot recognize this situation > > ... > > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -699,7 +699,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > * pages requested were isolated. If there were any failures, 0 is > * returned and CMA will fail. > */ > - if (strict && blockpfn < end_pfn) > + if (strict && (blockpfn < end_pfn || total_isolated != nr_scanned)) > total_isolated = 0; > > cc->total_free_scanned += nr_scanned; That's really old code. What userspace-visible effects might this have? Is this from code inspection, or was some misbehaviour observed? Thanks.
