Messages in this thread | | | Date | Mon, 9 Jan 2023 10:36:44 -0600 | Subject | Re: [PATCH mm-unstable 8/8] mm/hugetlb: convert demote_free_huge_page to folios | From | Sidhartha Kumar <> |
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On 1/7/23 2:55 PM, Mike Kravetz wrote: > On 01/07/23 01:31, Matthew Wilcox wrote: >> On Fri, Jan 06, 2023 at 05:11:36PM -0800, Mike Kravetz wrote: >>> On 01/03/23 13:13, Sidhartha Kumar wrote: >>>> @@ -3477,15 +3477,15 @@ static int demote_free_huge_page(struct hstate *h, struct page *page) >>>> mutex_lock(&target_hstate->resize_lock); >>>> for (i = 0; i < pages_per_huge_page(h); >>>> i += pages_per_huge_page(target_hstate)) { >>>> - subpage = nth_page(page, i); >>>> - folio = page_folio(subpage); >>>> + subpage = folio_page(folio, i); >>>> + subfolio = page_folio(subpage); >>> >>> No problems with the code, but I am not in love with the name subfolio. >>> I know it is patterned after 'subpage'. For better or worse, the term >>> subpage is used throughout the kernel. This would be the first usage of >>> the term 'subfolio'. >>> >>> Matthew do you have any comments on the naming? It is local to hugetlb, >>> but I would hate to see use of the term subfolio based on its introduction >>> here. >> >> I'm really not a fan of it either. I intended to dive into this patch >> and understand the function it's modifying, in the hopes of suggesting >> a better name and/or method. > > At a high level, this routine is splitting a very large folio (1G for > example) into multiple large folios of a smaller size (512 2M folios for > example). The loop is iterating through the very large folio at > increments of the smaller large folio. subfolio (previously subpage) is > used to point to the smaller large folio within the loop. > If folio does not need to be part of the variable name, how about something like 'demote_target'? The prep call inside the loop would then look like:
prep_new_hugetlb_folio(target_hstate, demote_target, nid);
so it is still clear that demote_target is a folio. A more concise version could also be 'demote_dst' but that seems more ambiguous than target.
Thanks, Sidhartha Kumar
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