From: Christoph Hellwig <hch@infradead.org>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
jgg@nvidia.com, peterx@redhat.com
Subject: Re: [PATCH 6/7] vfio: Add vfio_device_io_remap_mapping_range()
Date: Tue, 10 Aug 2021 11:04:03 +0200 [thread overview]
Message-ID: <YRJBA0A7vIF6PKMB@infradead.org> (raw)
In-Reply-To: <162818329235.1511194.15804833796430403640.stgit@omen>
> +int vfio_device_io_remap_mapping_range(struct vfio_device *device,
> + loff_t start, loff_t len)
> +{
> + struct address_space *mapping = device->inode->i_mapping;
> + int ret = 0;
> +
> + i_mmap_lock_write(mapping);
> + if (mapping_mapped(mapping)) {
> + struct rb_root_cached *root = &mapping->i_mmap;
> + pgoff_t pgstart = start >> PAGE_SHIFT;
> + pgoff_t pgend = (start + len - 1) >> PAGE_SHIFT;
> + struct vm_area_struct *vma;
> +
> + vma_interval_tree_foreach(vma, root, pgstart, pgend) {
There is no need for the mapping_mapped check here,
vma_interval_tree_foreach will the right thing for an empty tree.
That also allows to move a few more instructions out of the lock.
> + /*
> + * Force NOFS memory allocation context to avoid
> + * deadlock while we hold i_mmap_rwsem.
> + */
> + flags = memalloc_nofs_save();
Please move this out of the loop.
> +extern int vfio_device_io_remap_mapping_range(struct vfio_device *device,
> + loff_t start, loff_t len);
No need for the extern.
next prev parent reply other threads:[~2021-08-10 9:04 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-05 17:06 [PATCH 0/7] vfio: device fd address space and vfio-pci mmap invalidation cleanup Alex Williamson
2021-08-05 17:07 ` [PATCH 1/7] vfio: Create vfio_fs_type with inode per device Alex Williamson
2021-08-10 8:43 ` Christoph Hellwig
2021-08-10 14:52 ` Alex Williamson
2021-08-10 14:57 ` Christoph Hellwig
2021-08-10 18:49 ` Peter Xu
2021-08-10 21:16 ` Alex Williamson
2021-08-10 22:18 ` Peter Xu
2021-08-05 17:07 ` [PATCH 2/7] vfio: Export unmap_mapping_range() wrapper Alex Williamson
2021-08-10 8:45 ` Christoph Hellwig
2021-08-10 18:56 ` Peter Xu
2021-08-05 17:07 ` [PATCH 3/7] vfio/pci: Use vfio_device_unmap_mapping_range() Alex Williamson
2021-08-06 1:04 ` Jason Gunthorpe
2021-08-06 20:17 ` Alex Williamson
2021-08-10 8:51 ` Christoph Hellwig
2021-08-10 11:57 ` Jason Gunthorpe
2021-08-10 12:55 ` Christoph Hellwig
2021-08-10 21:50 ` Alex Williamson
2021-08-11 11:57 ` Jason Gunthorpe
2021-08-10 8:53 ` Christoph Hellwig
2021-08-10 19:02 ` Peter Xu
2021-08-10 20:51 ` Alex Williamson
2021-08-10 18:48 ` Peter Xu
2021-08-10 19:59 ` Alex Williamson
2021-08-10 20:20 ` Peter Xu
2021-08-05 17:07 ` [PATCH 4/7] vfio,vfio-pci: Add vma to pfn callback Alex Williamson
2021-08-06 1:01 ` Jason Gunthorpe
2021-08-10 9:00 ` Christoph Hellwig
2021-08-10 9:00 ` Christoph Hellwig
2021-08-05 17:08 ` [PATCH 5/7] mm/interval_tree.c: Export vma interval tree iterators Alex Williamson
2021-08-05 17:08 ` [PATCH 6/7] vfio: Add vfio_device_io_remap_mapping_range() Alex Williamson
2021-08-10 9:04 ` Christoph Hellwig [this message]
2021-08-05 17:08 ` [PATCH 7/7] vfio/pci: Remove map-on-fault behavior Alex Williamson
2021-08-10 9:11 ` Christoph Hellwig
2021-08-10 15:04 ` Alex Williamson
2021-08-10 20:54 ` Peter Xu
2021-08-10 21:45 ` Alex Williamson
2021-08-10 22:27 ` Peter Xu
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