From: Ralph Campbell <rcampbell@nvidia.com> To: <nouveau@lists.freedesktop.org>, <linux-rdma@vger.kernel.org>, <linux-mm@kvack.org>, <linux-kselftest@vger.kernel.org>, <linux-kernel@vger.kernel.org> Cc: Jerome Glisse <jglisse@redhat.com>, John Hubbard <jhubbard@nvidia.com>, Christoph Hellwig <hch@lst.de>, Jason Gunthorpe <jgg@mellanox.com>, "Ben Skeggs" <bskeggs@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Shuah Khan <shuah@linuxfoundation.org>, Ralph Campbell <rcampbell@nvidia.com> Subject: [PATCH 4/6] mm/hmm: add output flag for compound page mapping Date: Fri, 8 May 2020 12:20:07 -0700 [thread overview] Message-ID: <20200508192009.15302-5-rcampbell@nvidia.com> (raw) In-Reply-To: <20200508192009.15302-1-rcampbell@nvidia.com> hmm_range_fault() returns an array of page frame numbers and flags for how the pages are mapped in the requested process' page tables. The PFN can be used to get the struct page with hmm_pfn_to_page() and the page size order can be determined with compound_order(page) but if the page is larger than order 0 (PAGE_SIZE), there is no indication that the page is mapped using a larger page size. To be fully general, hmm_range_fault() would need to return the mapping size to handle cases like a 1GB compound page being mapped with 2MB PMD entries. However, the most common case is the mapping size the same as the underlying compound page size. Add a new output flag to indicate this so that callers know it is safe to use a large device page table mapping if one is available. Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> --- include/linux/hmm.h | 4 +++- mm/hmm.c | 10 +++++++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index e912b9dc4633..f2d38af421e7 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -41,12 +41,14 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), + HMM_PFN_COMPOUND = 1UL << (BITS_PER_LONG - 4), /* Input flags */ HMM_PFN_REQ_FAULT = HMM_PFN_VALID, HMM_PFN_REQ_WRITE = HMM_PFN_WRITE, - HMM_PFN_FLAGS = HMM_PFN_VALID | HMM_PFN_WRITE | HMM_PFN_ERROR, + HMM_PFN_FLAGS = HMM_PFN_VALID | HMM_PFN_WRITE | HMM_PFN_ERROR | + HMM_PFN_COMPOUND, }; /* diff --git a/mm/hmm.c b/mm/hmm.c index 41673a6d8d46..a9dd06e190a1 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -170,7 +170,9 @@ static inline unsigned long pmd_to_hmm_pfn_flags(struct hmm_range *range, { if (pmd_protnone(pmd)) return 0; - return pmd_write(pmd) ? (HMM_PFN_VALID | HMM_PFN_WRITE) : HMM_PFN_VALID; + return pmd_write(pmd) ? + (HMM_PFN_VALID | HMM_PFN_COMPOUND | HMM_PFN_WRITE) : + (HMM_PFN_VALID | HMM_PFN_COMPOUND); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -389,7 +391,9 @@ static inline unsigned long pud_to_hmm_pfn_flags(struct hmm_range *range, { if (!pud_present(pud)) return 0; - return pud_write(pud) ? (HMM_PFN_VALID | HMM_PFN_WRITE) : HMM_PFN_VALID; + return pud_write(pud) ? + (HMM_PFN_VALID | HMM_PFN_COMPOUND | HMM_PFN_WRITE) : + (HMM_PFN_VALID | HMM_PFN_COMPOUND); } static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, @@ -484,7 +488,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); for (; addr < end; addr += PAGE_SIZE, i++, pfn++) - range->hmm_pfns[i] = pfn | cpu_flags; + range->hmm_pfns[i] = pfn | cpu_flags | HMM_PFN_COMPOUND; spin_unlock(ptl); return 0; -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Ralph Campbell <rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> To: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Ralph Campbell <rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>, Jason Gunthorpe <jgg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>, Ben Skeggs <bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Shuah Khan <shuah-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org> Subject: [PATCH 4/6] mm/hmm: add output flag for compound page mapping Date: Fri, 8 May 2020 12:20:07 -0700 [thread overview] Message-ID: <20200508192009.15302-5-rcampbell@nvidia.com> (raw) In-Reply-To: <20200508192009.15302-1-rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> hmm_range_fault() returns an array of page frame numbers and flags for how the pages are mapped in the requested process' page tables. The PFN can be used to get the struct page with hmm_pfn_to_page() and the page size order can be determined with compound_order(page) but if the page is larger than order 0 (PAGE_SIZE), there is no indication that the page is mapped using a larger page size. To be fully general, hmm_range_fault() would need to return the mapping size to handle cases like a 1GB compound page being mapped with 2MB PMD entries. However, the most common case is the mapping size the same as the underlying compound page size. Add a new output flag to indicate this so that callers know it is safe to use a large device page table mapping if one is available. Signed-off-by: Ralph Campbell <rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- include/linux/hmm.h | 4 +++- mm/hmm.c | 10 +++++++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index e912b9dc4633..f2d38af421e7 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -41,12 +41,14 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), + HMM_PFN_COMPOUND = 1UL << (BITS_PER_LONG - 4), /* Input flags */ HMM_PFN_REQ_FAULT = HMM_PFN_VALID, HMM_PFN_REQ_WRITE = HMM_PFN_WRITE, - HMM_PFN_FLAGS = HMM_PFN_VALID | HMM_PFN_WRITE | HMM_PFN_ERROR, + HMM_PFN_FLAGS = HMM_PFN_VALID | HMM_PFN_WRITE | HMM_PFN_ERROR | + HMM_PFN_COMPOUND, }; /* diff --git a/mm/hmm.c b/mm/hmm.c index 41673a6d8d46..a9dd06e190a1 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -170,7 +170,9 @@ static inline unsigned long pmd_to_hmm_pfn_flags(struct hmm_range *range, { if (pmd_protnone(pmd)) return 0; - return pmd_write(pmd) ? (HMM_PFN_VALID | HMM_PFN_WRITE) : HMM_PFN_VALID; + return pmd_write(pmd) ? + (HMM_PFN_VALID | HMM_PFN_COMPOUND | HMM_PFN_WRITE) : + (HMM_PFN_VALID | HMM_PFN_COMPOUND); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -389,7 +391,9 @@ static inline unsigned long pud_to_hmm_pfn_flags(struct hmm_range *range, { if (!pud_present(pud)) return 0; - return pud_write(pud) ? (HMM_PFN_VALID | HMM_PFN_WRITE) : HMM_PFN_VALID; + return pud_write(pud) ? + (HMM_PFN_VALID | HMM_PFN_COMPOUND | HMM_PFN_WRITE) : + (HMM_PFN_VALID | HMM_PFN_COMPOUND); } static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, @@ -484,7 +488,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); for (; addr < end; addr += PAGE_SIZE, i++, pfn++) - range->hmm_pfns[i] = pfn | cpu_flags; + range->hmm_pfns[i] = pfn | cpu_flags | HMM_PFN_COMPOUND; spin_unlock(ptl); return 0; -- 2.20.1
next prev parent reply other threads:[~2020-05-08 19:20 UTC|newest] Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-08 19:20 [PATCH 0/6] nouveau/hmm: add support for mapping large pages Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:20 ` [PATCH 1/6] nouveau/hmm: map pages after migration Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:20 ` [PATCH 2/6] nouveau: make nvkm_vmm_ctor() and nvkm_mmu_ptp_get() static Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:20 ` [PATCH 3/6] nouveau/hmm: fault one page at a time Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell [this message] 2020-05-08 19:20 ` [PATCH 4/6] mm/hmm: add output flag for compound page mapping Ralph Campbell 2020-05-08 19:51 ` Christoph Hellwig 2020-05-08 19:51 ` Christoph Hellwig 2020-05-08 20:06 ` Ralph Campbell 2020-05-08 20:06 ` Ralph Campbell 2020-05-26 22:29 ` Zi Yan 2020-05-26 22:29 ` Zi Yan 2020-05-26 22:47 ` Ralph Campbell 2020-05-26 22:47 ` Ralph Campbell 2020-05-08 19:20 ` [PATCH 5/6] nouveau/hmm: support mapping large sysmem pages Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:20 ` [PATCH 6/6] hmm: add tests for HMM_PFN_COMPOUND flag Ralph Campbell 2020-05-08 19:20 ` Ralph Campbell 2020-05-08 19:59 ` [PATCH 0/6] nouveau/hmm: add support for mapping large pages Matthew Wilcox 2020-05-08 20:17 ` Ralph Campbell 2020-05-08 20:17 ` Ralph Campbell 2020-05-09 3:17 ` Matthew Wilcox 2020-05-09 3:17 ` Matthew Wilcox 2020-05-11 17:07 ` Ralph Campbell 2020-05-11 17:07 ` Ralph Campbell 2020-05-25 13:41 ` Jason Gunthorpe 2020-05-25 13:41 ` Jason Gunthorpe 2020-05-26 17:32 ` Ralph Campbell 2020-05-26 17:32 ` Ralph Campbell 2020-05-29 23:24 ` Jason Gunthorpe 2020-05-29 23:24 ` Jason Gunthorpe
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