Re: [PATCH 3/4] mm: simplify device private page handling in hmm_range_fault

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 3/19/20 5:14 PM, Jason Gunthorpe wrote:
On Tue, Mar 17, 2020 at 04:14:31PM -0700, Ralph Campbell wrote:

+static int dmirror_fault(struct dmirror *dmirror, unsigned long start,
+			 unsigned long end, bool write)
+{
+	struct mm_struct *mm = dmirror->mm;
+	unsigned long addr;
+	uint64_t pfns[64];
+	struct hmm_range range = {
+		.notifier = &dmirror->notifier,
+		.pfns = pfns,
+		.flags = dmirror_hmm_flags,
+		.values = dmirror_hmm_values,
+		.pfn_shift = DPT_SHIFT,
+		.pfn_flags_mask = ~(dmirror_hmm_flags[HMM_PFN_VALID] |
+				    dmirror_hmm_flags[HMM_PFN_WRITE]),

Since pfns is not initialized pfn_flags_mask should be 0.

Good point.

+		.default_flags = dmirror_hmm_flags[HMM_PFN_VALID] |
+				(write ? dmirror_hmm_flags[HMM_PFN_WRITE] : 0),
+		.dev_private_owner = dmirror->mdevice,
+	};
+	int ret = 0;

+static int dmirror_snapshot(struct dmirror *dmirror,
+			    struct hmm_dmirror_cmd *cmd)
+{
+	struct mm_struct *mm = dmirror->mm;
+	unsigned long start, end;
+	unsigned long size = cmd->npages << PAGE_SHIFT;
+	unsigned long addr;
+	unsigned long next;
+	uint64_t pfns[64];
+	unsigned char perm[64];
+	char __user *uptr;
+	struct hmm_range range = {
+		.pfns = pfns,
+		.flags = dmirror_hmm_flags,
+		.values = dmirror_hmm_values,
+		.pfn_shift = DPT_SHIFT,
+		.pfn_flags_mask = ~0ULL,

Same here, especially since this is snapshot

Jason

Actually, snapshot ignores pfn_flags_mask and default_flags.
In hmm_pte_need_fault(), HMM_FAULT_SNAPSHOT is checked and returns early before
checking pfn_flags_mask and default_flags since no faults are being requested.

_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx



[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux