On 2/28/25 10:52, Brendan Jackman wrote: > There's lots of text here but it's a little hard to follow, this is an > attempt to break it up and align its structure more closely with the > code. > > Reword the top-level function comment to just explain what question the > function answers from the point of view of the caller. > > Break up the internal logic into different sections that can have their > own commentary describing why that part of the rationale is present. > > Note the page_group_by_mobility_disabled logic is not explained in the > commentary, that is outside the scope of this patch... > > Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> > + /* > + * Unmovable/reclaimable allocations would cause permanent > + * fragmentations if they fell back to allocating from a movable block > + * (polluting it), so we try to claim the whole block regardless of the > + * allocation size. Later movable allocations can always steal from this > + * block, which is less problematic. > + */ > + if (start_mt == MIGRATE_RECLAIMABLE || start_mt == MIGRATE_UNMOVABLE) > + return true; > + > + if (page_group_by_mobility_disabled) > + return true; > + > + /* > + * Movable pages won't cause permanent fragmentation, so when you alloc s/you/we/ for consistency? I think Andrew can amend locally to avoid resend. Thanks. > + * small pages, we just need to temporarily steal unmovable or > + * reclaimable pages that are closest to the request size. After a > + * while, memory compaction may occur to form large contiguous pages, > + * and the next movable allocation may not need to steal. > + */ > return false; > } > >
