On Mon, Mar 10, 2025 at 10:28:02AM +0200, Mike Rapoport wrote: >Hi Wei, > >On Mon, Mar 10, 2025 at 07:56:27AM +0000, Wei Yang wrote: >> On Wed, Feb 26, 2025 at 02:09:15AM +0000, Wei Yang wrote: >> >>> >> >>> From the above call flow and background, there are three cases when >> >>> memblock_alloc_range_nid() would be called: >> >>> >> >>> * If it is called before (1), memblock.reserved's nid would be adjusted correctly. >> >>> * If it is called after (2), we don't touch memblock.reserved. >> >>> * If it happens between (1) and (2), it looks would break the consistency of >> >>> nid information in memblock.reserved. Because when we use >> >>> memblock_reserve_kern(), NUMA_NO_NODE would be stored in region. >> >>> >> >>> So my question is if the third case happens, would it introduce a bug? If it >> >>> won't happen, seems we don't need to specify the nid here? >> >> >> >>We don't really care about proper assignment of nodes between (1) and (2) >> >>from one side and the third case does not happen on the other side. Nothing >> >>should call membloc_alloc() after memblock_free_all(). >> >> >> > >> >My point is if no one would call memblock_alloc() after memblock_free_all(), >> >which set nid in memblock.reserved properly, it seems not necessary to do >> >__memblock_reserve() with exact nid during memblock_alloc()? >> > >> >As you did __memblock_reserve(found, size, nid, MEMBLOCK_RSRV_KERN) in this >> >patch. >> > >> >> Hi, Mike >> >> Do you think my understanding is reasonable? > >Without KHO it is indeed not strictly necessary to set nid during memblock_alloc(). >But since we anyway have nid parameter in memblock_alloc_range_nid() and it >anyway propagates to memblock_add_range(), I think it's easier and cleaner >to pass nid to __memblock_reserve() there. > >And for KHO estimation of scratch size it is important to have nid assigned to >the reserved areas before memblock_free_all(), at least for the allocations >that request particular nid explicitly. Thanks, I see your point. > >> -- >> Wei Yang >> Help you, Help me > >-- >Sincerely yours, >Mike. -- Wei Yang Help you, Help me
