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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 3B70D18001F X-Stat-Signature: tr55zt8admwqm9fua9oxc3prxr5r1z4x X-Rspam-User: X-HE-Tag: 1678984471-796719 X-HE-Meta: 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 kTUYzLa2 r45mqTHqRh8vB7m2voJV4y/zsXPCY485vCBkmiM2Mcyh9o885RVMOJCYaFXY35Lzs7OyPRgR4IYyvYBfWW5JHzJelfxOIKkRomQ+6h/MJedX2PQ1awkS2wi5gXNN6tcZ9dJQlca5EjZ64cfCF+9Gf2KkyeDlQbtkgYxvJoQa5KBh24yWG9C6Cn0Shn9MeImh81b2uWqdM0dF2t8/5PKl6qDGwsGdu0CfdmpQ5d+IHTMB6Rh3BEt4akg3WRBgaeLRNzm88t7dJJO1ma7alyvHvP0oG5+UbjV0aNCqohVFOkMHSSVQ7O7co8nCVlKfNiNJtpO50QF/Zu0qZ8/7x6YtcD4DggnpB7RVb43UWpHy9ADpeqEM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 16/03/2023 16:27, Yin, Fengwei wrote: > Hi Matthew, > > On 3/16/2023 12:08 AM, Ryan Roberts wrote: >> On 15/03/2023 13:34, Ryan Roberts wrote: >>> On 15/03/2023 05:14, Matthew Wilcox (Oracle) wrote: >>>> From: Yin Fengwei >>>> >>>> folio_add_file_rmap_range() allows to add pte mapping to a specific >>>> range of file folio. Comparing to page_add_file_rmap(), it batched >>>> updates __lruvec_stat for large folio. >>>> >>>> Signed-off-by: Yin Fengwei >>>> Signed-off-by: Matthew Wilcox (Oracle) >>>> --- >>>> include/linux/rmap.h | 2 ++ >>>> mm/rmap.c | 60 +++++++++++++++++++++++++++++++++----------- >>>> 2 files changed, 48 insertions(+), 14 deletions(-) >>>> >>>> diff --git a/include/linux/rmap.h b/include/linux/rmap.h >>>> index b87d01660412..a3825ce81102 100644 >>>> --- a/include/linux/rmap.h >>>> +++ b/include/linux/rmap.h >>>> @@ -198,6 +198,8 @@ void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *, >>>> unsigned long address); >>>> void page_add_file_rmap(struct page *, struct vm_area_struct *, >>>> bool compound); >>>> +void folio_add_file_rmap_range(struct folio *, struct page *, unsigned int nr, >>>> + struct vm_area_struct *, bool compound); >>>> void page_remove_rmap(struct page *, struct vm_area_struct *, >>>> bool compound); >>>> >>>> diff --git a/mm/rmap.c b/mm/rmap.c >>>> index 4898e10c569a..a91906b28835 100644 >>>> --- a/mm/rmap.c >>>> +++ b/mm/rmap.c >>>> @@ -1301,31 +1301,39 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, >>>> } >>>> >>>> /** >>>> - * page_add_file_rmap - add pte mapping to a file page >>>> - * @page: the page to add the mapping to >>>> + * folio_add_file_rmap_range - add pte mapping to page range of a folio >>>> + * @folio: The folio to add the mapping to >>>> + * @page: The first page to add >>>> + * @nr_pages: The number of pages which will be mapped >>>> * @vma: the vm area in which the mapping is added >>>> * @compound: charge the page as compound or small page >>>> * >>>> + * The page range of folio is defined by [first_page, first_page + nr_pages) >>>> + * >>>> * The caller needs to hold the pte lock. >>>> */ >>>> -void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, >>>> - bool compound) >>>> +void folio_add_file_rmap_range(struct folio *folio, struct page *page, >>>> + unsigned int nr_pages, struct vm_area_struct *vma, >>>> + bool compound) >>>> { >>>> - struct folio *folio = page_folio(page); >>>> atomic_t *mapped = &folio->_nr_pages_mapped; >>>> - int nr = 0, nr_pmdmapped = 0; >>>> - bool first; >>>> + unsigned int nr_pmdmapped = 0, first; >>>> + int nr = 0; >>>> >>>> - VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page); >>>> + VM_WARN_ON_FOLIO(compound && !folio_test_pmd_mappable(folio), folio); >>>> >>>> /* Is page being mapped by PTE? Is this its first map to be added? */ >>>> if (likely(!compound)) { >>>> - first = atomic_inc_and_test(&page->_mapcount); >>>> - nr = first; >>>> - if (first && folio_test_large(folio)) { >>>> - nr = atomic_inc_return_relaxed(mapped); >>>> - nr = (nr < COMPOUND_MAPPED); >>>> - } >>>> + do { >>>> + first = atomic_inc_and_test(&page->_mapcount); >>>> + if (first && folio_test_large(folio)) { >>>> + first = atomic_inc_return_relaxed(mapped); >>>> + first = (nr < COMPOUND_MAPPED); >>> >>> This still contains the typo that Yin Fengwei spotted in the previous version: >>> https://lore.kernel.org/linux-mm/20230228213738.272178-1-willy@infradead.org/T/#m84673899e25bc31356093a1177941f2cc35e5da8 >>> >>> FYI, I'm seeing a perf regression of about 1% when compiling the kernel on >>> Ampere Altra (arm64) with this whole series on top of v6.3-rc1 (In a VM using >>> ext4 filesystem). Looks like instruction aborts are taking much longer and a >>> selection of syscalls are a bit slower. Still hunting down the root cause. Will >>> report once I have conclusive diagnosis. >> >> I'm sorry - I'm struggling to find the exact cause. But its spending over 2x the >> amount of time in the instruction abort handling code once patches 32-36 are >> included. Everything in the flame graph is just taking longer. Perhaps we are >> getting more instruction aborts somehow? I have the flamegraphs if anyone wants >> them - just shout and I'll email them separately. > Thanks a lot to Ryan for sharing the flamegraphs to me. I found the __do_fault() > is called with patch 32-36 while no __do_fault() just with first 31 patches. I > suspect the folio_add_file_rmap_range() missed some PTEs population. Please give > me few days to find the root cause and fix. Sorry for this. You're welcome. Give me a shout once you have a re-spin and I'll rerun the tests. > > > Regards > Yin, Fengwei > >> >>> >>> Thanks, >>> Ryan >>> >>> >>>> + } >>>> + >>>> + if (first) >>>> + nr++; >>>> + } while (page++, --nr_pages > 0); >>>> } else if (folio_test_pmd_mappable(folio)) { >>>> /* That test is redundant: it's for safety or to optimize out */ >>>> >>>> @@ -1354,6 +1362,30 @@ void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, >>>> mlock_vma_folio(folio, vma, compound); >>>> } >>>> >>>> +/** >>>> + * page_add_file_rmap - add pte mapping to a file page >>>> + * @page: the page to add the mapping to >>>> + * @vma: the vm area in which the mapping is added >>>> + * @compound: charge the page as compound or small page >>>> + * >>>> + * The caller needs to hold the pte lock. >>>> + */ >>>> +void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, >>>> + bool compound) >>>> +{ >>>> + struct folio *folio = page_folio(page); >>>> + unsigned int nr_pages; >>>> + >>>> + VM_WARN_ON_ONCE_PAGE(compound && !PageTransHuge(page), page); >>>> + >>>> + if (likely(!compound)) >>>> + nr_pages = 1; >>>> + else >>>> + nr_pages = folio_nr_pages(folio); >>>> + >>>> + folio_add_file_rmap_range(folio, page, nr_pages, vma, compound); >>>> +} >>>> + >>>> /** >>>> * page_remove_rmap - take down pte mapping from a page >>>> * @page: page to remove mapping from >>> >>