Commit 96268163 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jason Gunthorpe
Browse files

mm/hmm: remove the unused HMM_FAULT_ALLOW_RETRY flag 

The HMM_FAULT_ALLOW_RETRY isn't used anywhere in the tree.  Remove it and
the weird -EAGAIN handling where handle_mm_fault() drops the mmap_sem.

Link: https://lore.kernel.org/r/20200316135310.899364-3-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent ddfaed17

include/linux/hmm.h

+0 −5
Original line number Diff line number Diff line
@@ -217,11 +217,6 @@ static inline uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, 
		range->flags[HMM_PFN_VALID];

}



/*

 * Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case.

 */

#define HMM_FAULT_ALLOW_RETRY		(1 << 0)



/* Don't fault in missing PTEs, just snapshot the current state. */

#define HMM_FAULT_SNAPSHOT		(1 << 1)

mm/hmm.c

+0 −7
Original line number Diff line number Diff line
@@ -45,16 +45,10 @@ static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr, 
	if (!vma)

		goto err;



	if (hmm_vma_walk->flags & HMM_FAULT_ALLOW_RETRY)

		flags |= FAULT_FLAG_ALLOW_RETRY;

	if (write_fault)

		flags |= FAULT_FLAG_WRITE;



	ret = handle_mm_fault(vma, addr, flags);

	if (ret & VM_FAULT_RETRY) {

		/* Note, handle_mm_fault did up_read(&mm->mmap_sem)) */

		return -EAGAIN;

	}

	if (ret & VM_FAULT_ERROR)

		goto err;
@@ -662,7 +656,6 @@ static const struct mm_walk_ops hmm_walk_ops = { 
 * -ENOMEM:	Out of memory.

 * -EPERM:	Invalid permission (e.g., asking for write and range is read

 *		only).

 * -EAGAIN:	A page fault needs to be retried and mmap_sem was dropped.

 * -EBUSY:	The range has been invalidated and the caller needs to wait for

 *		the invalidation to finish.

 * -EFAULT:	Invalid (i.e., either no valid vma or it is illegal to access