similar to: [PATCH] mm: Take a page reference when removing device exclusive entries

Device exclusive page table entries are used to prevent CPU access to a page whilst it is being accessed from a device. Typically this is used to implement atomic operations when the underlying bus does not support atomic access. When a CPU thread encounters a device exclusive entry it locks the page and restores the original entry after calling mmu notifiers to signal drivers that exclusive

On Tue, Mar 28, 2023 at 01:14:34PM +1100, Alistair Popple wrote: > +++ b/mm/memory.c > @@ -3623,8 +3623,19 @@ static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf) > struct vm_area_struct *vma = vmf->vma; > struct mmu_notifier_range range; > > - if (!folio_lock_or_retry(folio, vma->vm_mm, vmf->flags)) > + /* > + * We need a page reference to

On 3/27/23 19:14, Alistair Popple wrote: > Device exclusive page table entries are used to prevent CPU access to > a page whilst it is being accessed from a device. Typically this is > used to implement atomic operations when the underlying bus does not > support atomic access. When a CPU thread encounters a device exclusive > entry it locks the page and restores the original entry

John Hubbard <jhubbard at nvidia.com> writes: > On 3/28/23 20:16, Matthew Wilcox wrote: > ... >>> + if (!get_page_unless_zero(vmf->page)) >>> + return 0; >> From a folio point of view: what the hell are you doing here? Tail >> pages don't have individual refcounts; all the refcounts are actually I had stuck with using the page because none of

On 3/28/23 20:16, Matthew Wilcox wrote: ... >> + if (!get_page_unless_zero(vmf->page)) >> + return 0; > > From a folio point of view: what the hell are you doing here? Tail > pages don't have individual refcounts; all the refcounts are actually ohh, and I really should have caught that too. I plead spending too much time recently in a somewhat more driver-centric

One fix and a minor cleanup. Only compile-tested due to lack of HW, so I'd be happy if someone with access to HW could test. But not sure how easy this is to trigger. Likely some concurrent MADV_DONTNEED on the PTE we just converted might be able to trigger it. Cc: Karol Herbst <kherbst at redhat.com> Cc: Lyude Paul <lyude at redhat.com> Cc: Danilo Krummrich <dakr at

"Zhou, Xianrong" <Xianrong.Zhou at amd.com> writes: > [AMD Official Use Only - General] > >> >>>>> The vmf_insert_pfn_prot could cause unnecessary double faults on a >> >>>>> device pfn. Because currently the vmf_insert_pfn_prot does not >> >>>>> make the pfn writable so the pte entry is normally read-only or

*** BLURB HERE *** Bean Huo (5): fs/buffer: clean up block_commit_write fs/buffer.c: convert block_commit_write to return void ext4: No need to check return value of block_commit_write() fs/ocfs2: No need to check return value of block_commit_write() udf: No need to check return value of block_commit_write() fs/buffer.c | 24 +++++++-----------------

This series adds support for transparent huge page migration to migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers. Earlier versions were posted previously [1] and [2]. The patches apply cleanly to the linux-mm 5.10.0-rc2 tree. There are a lot of other THP patches being posted. I don't think there are any semantic conflicts but there may be some merge conflicts depending on

This series adds support for transparent huge page migration to migrate_vma_*() and adds nouveau SVM and HMM selftests as consumers. An earlier version was posted previously [1]. This version now supports splitting a THP midway in the migration process which led to a number of changes. The patches apply cleanly to the current linux-mm tree. Since there are a couple of patches in linux-mm from Dan

On Mon, 27 Mar 2023 23:25:49 -0700 John Hubbard <jhubbard at nvidia.com> wrote: > On the patch process, I see that this applies to linux-stable's 6.1.y > branch. I'd suggest two things: > > 1) Normally, what I've seen done is to post against either the current > top of tree linux.git, or else against one of the mm-stable branches. > And then after it's

These patches apply to linux-5.8.0-rc1. Patches 1-3 should probably go into 5.8, the others can be queued for 5.9. Patches 4-6 improve the HMM self tests. Patch 7-8 prepare nouveau for the meat of this series which adds support and testing for compound page mapping of system memory (patches 9-11) and compound page migration to device private memory (patches 12-16). Since these changes are split

Changelog: v1--v2: 1. Re-order patches to avoid breaking compilation. Bean Huo (5): fs/buffer: clean up block_commit_write ext4: No need to check return value of block_commit_write() fs/ocfs2: No need to check return value of block_commit_write() udf: No need to check return value of block_commit_write() fs/buffer.c: convert block_commit_write to return void fs/buffer.c

On Wed, Jun 26, 2019 at 02:27:11PM +0200, Christoph Hellwig wrote: > This replaces the hacky ->fault callback, which is currently directly > called from common code through a hmm specific data structure as an > exercise in layering violations. > > Signed-off-by: Christoph Hellwig <hch at lst.de> > Reviewed-by: Ralph Campbell <rcampbell at nvidia.com> > --- >

The fault code has been calling file_update_time after ->page_mkwrite after it drops the page lock, but this is annoying because this calls mark_inode_dirty which can fail in Btrfs, so we want to be able to do these updates in ->page_mkwrite so we can get an error back to the user. So get rid of the file_update_time calls in the fault code and push it into everybody who has a

Hello Christian K?nig, The patch 141b15e59175: "drm/nouveau: move io_reserve_lru handling into the driver v5" from Aug 21, 2020, leads to the following static checker warning: drivers/gpu/drm/nouveau/nouveau_ttm.c:148 nouveau_ttm_fault() warn: inconsistent returns '*bo->base.resv'. drivers/gpu/drm/nouveau/nouveau_ttm.c 126 static vm_fault_t nouveau_ttm_fault(struct

A copy push command might fail, causing `migrate_to_ram` to return a dirty HIGH_USER page to the user. This exposes a security vulnerability in the nouveau driver. To prevent memory leaks in `migrate_to_ram` upon a copy error, allocate a zero page for the destination page. Signed-off-by: Yonatan Maman <Ymaman at Nvidia.com> Signed-off-by: Gal Shalom <GalShalom at Nvidia.com> ---

Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on vhost/linux-next] [also build test ERROR on linus/master v5.7 next-20200529] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see

Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on vhost/linux-next] [also build test ERROR on linus/master v5.7 next-20200529] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see

On 2020/6/2 ??12:56, Michael S. Tsirkin wrote: > On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot wrote: >> Hi Jason, >> >> I love your patch! Yet something to improve: >> >> [auto build test ERROR on vhost/linux-next] >> [also build test ERROR on linus/master v5.7 next-20200529] >> [if your patch is applied to the wrong git tree, please drop