On 2024/3/1 5:20, Matthew Wilcox (Oracle) wrote:
> Saves dozens of calls to compound_head().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/memory-failure.c | 40 +++++++++++++++++++++-------------------
> 1 file changed, 21 insertions(+), 19 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index fe4959e994d0..74e87a0a792c 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2189,7 +2189,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
> int memory_failure(unsigned long pfn, int flags)
> {
> struct page *p;
> - struct page *hpage;
> + struct folio *folio;
> struct dev_pagemap *pgmap;
> int res = 0;
> unsigned long page_flags;
> @@ -2277,8 +2277,8 @@ int memory_failure(unsigned long pfn, int flags)
> }
> }
>
> - hpage = compound_head(p);
> - if (PageTransHuge(hpage)) {
> + folio = page_folio(p);
> + if (folio_test_large(folio)) {
> /*
> * The flag must be set after the refcount is bumped
> * otherwise it may race with THP split.
> @@ -2292,12 +2292,13 @@ int memory_failure(unsigned long pfn, int flags)
> * or unhandlable page. The refcount is bumped iff the
> * page is a valid handlable page.
> */
> - SetPageHasHWPoisoned(hpage);
> + folio_set_has_hwpoisoned(folio);
> if (try_to_split_thp_page(p) < 0) {
> res = action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
> goto unlock_mutex;
> }
> VM_BUG_ON_PAGE(!page_count(p), p);
> + folio = page_folio(p);
> }
>
> /*
> @@ -2308,9 +2309,9 @@ int memory_failure(unsigned long pfn, int flags)
> * The check (unnecessarily) ignores LRU pages being isolated and
> * walked by the page reclaim code, however that's not a big loss.
> */
> - shake_page(p);
> + shake_folio(folio);
>
> - lock_page(p);
> + folio_lock(folio);
>
> /*
> * We're only intended to deal with the non-Compound page here.
> @@ -2318,11 +2319,11 @@ int memory_failure(unsigned long pfn, int flags)
> * race window. If this happens, we could try again to hopefully
> * handle the page next round.
> */
> - if (PageCompound(p)) {
> + if (folio_test_large(folio)) {
folio_test_large() only checks whether PG_head is set but PageCompound() also checks PageTail().
So folio_test_large() and PageCompound() are not equivalent?
Thanks.
