>> >> In order to fully utilize the memory chunk allocated from bootmem >> >> allocator, it'd better to assure memory sector descriptor won't run >> >> across the boundary (PAGE_SIZE). > >OK, I misread this part of the changelog changelog. > I should have clarified that more clear :-) >> > >> >Why? The memory is continuous, right? >> >> Yes, the memory is conginous and the capacity of specific entry >> in mem_section[NR_SECTION_ROOTS] has been defined as follows: >> >> >> #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) >> >> Also, the memory is prone to be allocated from bootmem by function >> alloc_bootmem_node(), which has PAGE_SIZE alignment. So I think it's >> reasonable to introduce the extra check here from my personal view :-) > >No it is not necessary because we will never cross the page boundary >because (SECTIONS_PER_ROOT uses an int division) Current situation is that we don't cross the page foundary, but somebody else might change the data struct (struct mem_section) in future. It will trigger warning at build time to alarm that the struct should fit with page size. Anyway, I will drop this in next revision if you want keep as of being. Otherwise, I will include it in next revision :-) Thanks for your time, Michal. Thanks, Gavin >-- >Michal Hocko >SUSE Labs >SUSE LINUX s.r.o. >Lihovarska 1060/12 >190 00 Praha 9 >Czech Republic > >-- >To unsubscribe, send a message with 'unsubscribe linux-mm' in >the body to majordomo@xxxxxxxxx. For more info on Linux MM, >see: http://www.linux-mm.org/ . >Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>