From: Joao Martins <joao.m.martins@oracle.com> To: linux-mm@kvack.org Cc: linux-nvdimm@lists.01.org, Matthew Wilcox <willy@infradead.org>, Jason Gunthorpe <jgg@ziepe.ca>, Muchun Song <songmuchun@bytedance.com>, Mike Kravetz <mike.kravetz@oracle.com>, Andrew Morton <akpm@linux-foundation.org>, Joao Martins <joao.m.martins@oracle.com> Subject: [PATCH RFC 7/9] mm/gup: Decrement head page once for group of subpages Date: Tue, 8 Dec 2020 17:28:59 +0000 [thread overview] Message-ID: <20201208172901.17384-9-joao.m.martins@oracle.com> (raw) In-Reply-To: <20201208172901.17384-1-joao.m.martins@oracle.com> Rather than decrementing the ref count one by one, we walk the page array and checking which belong to the same compound_head. Later on we decrement the calculated amount of references in a single write to the head page. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- mm/gup.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 194e6981eb03..3a9a7229f418 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -212,6 +212,18 @@ static bool __unpin_devmap_managed_user_page(struct page *page) } #endif /* CONFIG_DEV_PAGEMAP_OPS */ +static int record_refs(struct page **pages, int npages) +{ + struct page *head = compound_head(pages[0]); + int refs = 1, index; + + for (index = 1; index < npages; index++, refs++) + if (compound_head(pages[index]) != head) + break; + + return refs; +} + /** * unpin_user_page() - release a dma-pinned page * @page: pointer to page to be released @@ -221,9 +233,9 @@ static bool __unpin_devmap_managed_user_page(struct page *page) * that such pages can be separately tracked and uniquely handled. In * particular, interactions with RDMA and filesystems need special handling. */ -void unpin_user_page(struct page *page) +static void __unpin_user_page(struct page *page, int refs) { - int refs = 1; + int orig_refs = refs; page = compound_head(page); @@ -237,14 +249,19 @@ void unpin_user_page(struct page *page) return; if (hpage_pincount_available(page)) - hpage_pincount_sub(page, 1); + hpage_pincount_sub(page, refs); else - refs = GUP_PIN_COUNTING_BIAS; + refs *= GUP_PIN_COUNTING_BIAS; if (page_ref_sub_and_test(page, refs)) __put_page(page); - mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, 1); + mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, orig_refs); +} + +void unpin_user_page(struct page *page) +{ + __unpin_user_page(page, 1); } EXPORT_SYMBOL(unpin_user_page); @@ -274,6 +291,7 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, bool make_dirty) { unsigned long index; + int refs = 1; /* * TODO: this can be optimized for huge pages: if a series of pages is @@ -286,8 +304,9 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, return; } - for (index = 0; index < npages; index++) { + for (index = 0; index < npages; index += refs) { struct page *page = compound_head(pages[index]); + /* * Checking PageDirty at this point may race with * clear_page_dirty_for_io(), but that's OK. Two key @@ -310,7 +329,8 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, */ if (!PageDirty(page)) set_page_dirty_lock(page); - unpin_user_page(page); + refs = record_refs(pages + index, npages - index); + __unpin_user_page(page, refs); } } EXPORT_SYMBOL(unpin_user_pages_dirty_lock); @@ -327,6 +347,7 @@ EXPORT_SYMBOL(unpin_user_pages_dirty_lock); void unpin_user_pages(struct page **pages, unsigned long npages) { unsigned long index; + int refs = 1; /* * If this WARN_ON() fires, then the system *might* be leaking pages (by @@ -340,8 +361,10 @@ void unpin_user_pages(struct page **pages, unsigned long npages) * physically contiguous and part of the same compound page, then a * single operation to the head page should suffice. */ - for (index = 0; index < npages; index++) - unpin_user_page(pages[index]); + for (index = 0; index < npages; index += refs) { + refs = record_refs(pages + index, npages - index); + __unpin_user_page(pages[index], refs); + } } EXPORT_SYMBOL(unpin_user_pages); -- 2.17.1 _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
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From: Joao Martins <joao.m.martins@oracle.com> To: linux-mm@kvack.org Cc: Dan Williams <dan.j.williams@intel.com>, Ira Weiny <ira.weiny@intel.com>, linux-nvdimm@lists.01.org, Matthew Wilcox <willy@infradead.org>, Jason Gunthorpe <jgg@ziepe.ca>, Jane Chu <jane.chu@oracle.com>, Muchun Song <songmuchun@bytedance.com>, Mike Kravetz <mike.kravetz@oracle.com>, Andrew Morton <akpm@linux-foundation.org>, Joao Martins <joao.m.martins@oracle.com> Subject: [PATCH RFC 7/9] mm/gup: Decrement head page once for group of subpages Date: Tue, 8 Dec 2020 17:28:59 +0000 [thread overview] Message-ID: <20201208172901.17384-9-joao.m.martins@oracle.com> (raw) In-Reply-To: <20201208172901.17384-1-joao.m.martins@oracle.com> Rather than decrementing the ref count one by one, we walk the page array and checking which belong to the same compound_head. Later on we decrement the calculated amount of references in a single write to the head page. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- mm/gup.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 194e6981eb03..3a9a7229f418 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -212,6 +212,18 @@ static bool __unpin_devmap_managed_user_page(struct page *page) } #endif /* CONFIG_DEV_PAGEMAP_OPS */ +static int record_refs(struct page **pages, int npages) +{ + struct page *head = compound_head(pages[0]); + int refs = 1, index; + + for (index = 1; index < npages; index++, refs++) + if (compound_head(pages[index]) != head) + break; + + return refs; +} + /** * unpin_user_page() - release a dma-pinned page * @page: pointer to page to be released @@ -221,9 +233,9 @@ static bool __unpin_devmap_managed_user_page(struct page *page) * that such pages can be separately tracked and uniquely handled. In * particular, interactions with RDMA and filesystems need special handling. */ -void unpin_user_page(struct page *page) +static void __unpin_user_page(struct page *page, int refs) { - int refs = 1; + int orig_refs = refs; page = compound_head(page); @@ -237,14 +249,19 @@ void unpin_user_page(struct page *page) return; if (hpage_pincount_available(page)) - hpage_pincount_sub(page, 1); + hpage_pincount_sub(page, refs); else - refs = GUP_PIN_COUNTING_BIAS; + refs *= GUP_PIN_COUNTING_BIAS; if (page_ref_sub_and_test(page, refs)) __put_page(page); - mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, 1); + mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, orig_refs); +} + +void unpin_user_page(struct page *page) +{ + __unpin_user_page(page, 1); } EXPORT_SYMBOL(unpin_user_page); @@ -274,6 +291,7 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, bool make_dirty) { unsigned long index; + int refs = 1; /* * TODO: this can be optimized for huge pages: if a series of pages is @@ -286,8 +304,9 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, return; } - for (index = 0; index < npages; index++) { + for (index = 0; index < npages; index += refs) { struct page *page = compound_head(pages[index]); + /* * Checking PageDirty at this point may race with * clear_page_dirty_for_io(), but that's OK. Two key @@ -310,7 +329,8 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, */ if (!PageDirty(page)) set_page_dirty_lock(page); - unpin_user_page(page); + refs = record_refs(pages + index, npages - index); + __unpin_user_page(page, refs); } } EXPORT_SYMBOL(unpin_user_pages_dirty_lock); @@ -327,6 +347,7 @@ EXPORT_SYMBOL(unpin_user_pages_dirty_lock); void unpin_user_pages(struct page **pages, unsigned long npages) { unsigned long index; + int refs = 1; /* * If this WARN_ON() fires, then the system *might* be leaking pages (by @@ -340,8 +361,10 @@ void unpin_user_pages(struct page **pages, unsigned long npages) * physically contiguous and part of the same compound page, then a * single operation to the head page should suffice. */ - for (index = 0; index < npages; index++) - unpin_user_page(pages[index]); + for (index = 0; index < npages; index += refs) { + refs = record_refs(pages + index, npages - index); + __unpin_user_page(pages[index], refs); + } } EXPORT_SYMBOL(unpin_user_pages); -- 2.17.1
next prev parent reply other threads:[~2020-12-08 17:30 UTC|newest] Thread overview: 147+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-08 17:28 [PATCH RFC 0/9] mm, sparse-vmemmap: Introduce compound pagemaps Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 1/9] memremap: add ZONE_DEVICE support for compound pages Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-09 5:59 ` John Hubbard 2020-12-09 5:59 ` John Hubbard 2020-12-09 6:33 ` Matthew Wilcox 2020-12-09 6:33 ` Matthew Wilcox 2020-12-09 13:12 ` Joao Martins 2020-12-09 13:12 ` Joao Martins 2021-02-20 1:43 ` Dan Williams 2021-02-20 1:43 ` Dan Williams 2021-02-22 11:24 ` Joao Martins 2021-02-22 11:24 ` Joao Martins 2021-02-22 20:37 ` Dan Williams 2021-02-22 20:37 ` Dan Williams 2021-02-23 15:46 ` Joao Martins 2021-02-23 15:46 ` Joao Martins 2021-02-23 16:50 ` Dan Williams 2021-02-23 16:50 ` Dan Williams 2021-02-23 17:18 ` Joao Martins 2021-02-23 17:18 ` Joao Martins 2021-02-23 18:18 ` Dan Williams 2021-02-23 18:18 ` Dan Williams 2021-03-10 18:12 ` Joao Martins 2021-03-10 18:12 ` Joao Martins 2021-03-12 5:54 ` Dan Williams 2021-03-12 5:54 ` Dan Williams 2021-02-20 1:24 ` Dan Williams 2021-02-20 1:24 ` Dan Williams 2021-02-22 11:09 ` Joao Martins 2021-02-22 11:09 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 2/9] sparse-vmemmap: Consolidate arguments in vmemmap section populate Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-09 6:16 ` John Hubbard 2020-12-09 6:16 ` John Hubbard 2020-12-09 13:51 ` Joao Martins 2020-12-09 13:51 ` Joao Martins 2021-02-20 1:49 ` Dan Williams 2021-02-20 1:49 ` Dan Williams 2021-02-22 11:26 ` Joao Martins 2021-02-22 11:26 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 3/9] sparse-vmemmap: Reuse vmemmap areas for a given mhp_params::align Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-08 17:38 ` Joao Martins 2020-12-08 17:38 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 3/9] sparse-vmemmap: Reuse vmemmap areas for a given page size Joao Martins 2020-12-08 17:28 ` Joao Martins 2021-02-20 3:34 ` Dan Williams 2021-02-20 3:34 ` Dan Williams 2021-02-22 11:42 ` Joao Martins 2021-02-22 11:42 ` Joao Martins 2021-02-22 22:40 ` Dan Williams 2021-02-22 22:40 ` Dan Williams 2021-02-23 15:46 ` Joao Martins 2021-02-23 15:46 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 4/9] mm/page_alloc: Reuse tail struct pages for compound pagemaps Joao Martins 2020-12-08 17:28 ` Joao Martins 2021-02-20 6:17 ` Dan Williams 2021-02-20 6:17 ` Dan Williams 2021-02-22 12:01 ` Joao Martins 2021-02-22 12:01 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 5/9] device-dax: Compound pagemap support Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-08 17:28 ` [PATCH RFC 6/9] mm/gup: Grab head page refcount once for group of subpages Joao Martins 2020-12-08 17:28 ` Joao Martins 2020-12-08 19:49 ` Jason Gunthorpe 2020-12-09 11:05 ` Joao Martins 2020-12-09 11:05 ` Joao Martins 2020-12-09 15:15 ` Jason Gunthorpe 2020-12-09 16:02 ` Joao Martins 2020-12-09 16:02 ` Joao Martins 2020-12-09 16:24 ` Jason Gunthorpe 2020-12-09 17:27 ` Joao Martins 2020-12-09 17:27 ` Joao Martins 2020-12-09 18:14 ` Matthew Wilcox 2020-12-09 18:14 ` Matthew Wilcox 2020-12-09 19:08 ` Jason Gunthorpe 2020-12-10 15:43 ` Joao Martins 2020-12-10 15:43 ` Joao Martins 2020-12-09 4:40 ` John Hubbard 2020-12-09 4:40 ` John Hubbard 2020-12-09 13:44 ` Joao Martins 2020-12-09 13:44 ` Joao Martins 2020-12-08 17:28 ` Joao Martins [this message] 2020-12-08 17:28 ` [PATCH RFC 7/9] mm/gup: Decrement head page " Joao Martins 2020-12-08 19:34 ` Jason Gunthorpe 2020-12-09 5:06 ` John Hubbard 2020-12-09 5:06 ` John Hubbard 2020-12-09 13:43 ` Jason Gunthorpe 2020-12-09 12:17 ` Joao Martins 2020-12-09 12:17 ` Joao Martins 2020-12-17 19:05 ` Joao Martins 2020-12-17 19:05 ` Joao Martins 2020-12-17 20:05 ` Jason Gunthorpe 2020-12-17 22:34 ` Joao Martins 2020-12-17 22:34 ` Joao Martins 2020-12-18 14:25 ` Jason Gunthorpe 2020-12-19 2:06 ` John Hubbard 2020-12-19 2:06 ` John Hubbard 2020-12-19 13:10 ` Joao Martins 2020-12-19 13:10 ` Joao Martins 2020-12-08 17:29 ` [PATCH RFC 8/9] RDMA/umem: batch page unpin in __ib_mem_release() Joao Martins 2020-12-08 17:29 ` Joao Martins 2020-12-08 19:29 ` Jason Gunthorpe 2020-12-09 10:59 ` Joao Martins 2020-12-09 10:59 ` Joao Martins 2020-12-19 13:15 ` Joao Martins 2020-12-19 13:15 ` Joao Martins 2020-12-09 5:18 ` John Hubbard 2020-12-09 5:18 ` John Hubbard 2020-12-08 17:29 ` [PATCH RFC 9/9] mm: Add follow_devmap_page() for devdax vmas Joao Martins 2020-12-08 17:29 ` Joao Martins 2020-12-08 19:57 ` Jason Gunthorpe 2020-12-09 8:05 ` Christoph Hellwig 2020-12-09 8:05 ` Christoph Hellwig 2020-12-09 11:19 ` Joao Martins 2020-12-09 11:19 ` Joao Martins 2020-12-09 5:23 ` John Hubbard 2020-12-09 5:23 ` John Hubbard 2020-12-09 9:38 ` [PATCH RFC 0/9] mm, sparse-vmemmap: Introduce compound pagemaps David Hildenbrand 2020-12-09 9:38 ` David Hildenbrand 2020-12-09 9:52 ` [External] " Muchun Song 2020-12-09 9:52 ` Muchun Song 2021-02-20 1:18 ` Dan Williams 2021-02-20 1:18 ` Dan Williams 2021-02-22 11:06 ` Joao Martins 2021-02-22 11:06 ` Joao Martins 2021-02-22 14:32 ` Joao Martins 2021-02-22 14:32 ` Joao Martins 2021-02-23 16:28 ` Joao Martins 2021-02-23 16:28 ` Joao Martins 2021-02-23 16:44 ` Dan Williams 2021-02-23 16:44 ` Dan Williams 2021-02-23 17:15 ` Joao Martins 2021-02-23 17:15 ` Joao Martins 2021-02-23 18:15 ` Dan Williams 2021-02-23 18:15 ` Dan Williams 2021-02-23 18:54 ` Jason Gunthorpe 2021-02-23 22:48 ` Dan Williams 2021-02-23 22:48 ` Dan Williams 2021-02-23 23:07 ` Jason Gunthorpe 2021-02-24 0:14 ` Dan Williams 2021-02-24 0:14 ` Dan Williams 2021-02-24 1:00 ` Jason Gunthorpe 2021-02-24 1:32 ` Dan Williams 2021-02-24 1:32 ` Dan Williams
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