drm/amdkfd: add function svm_migrate_successful_pages

to get migration pages. dst MIGRATE_PFN_VALID bit and src
MIGRATE_PFN_MIGRATE bit should always be set when migration success.

cpage includes src MIGRATE_PFN_MIGRATE bit set and MIGRATE_PFN_VALID
bit unset pages for both RAM and VRAM when memory is only allocated
without being populated before migration, those ram pages should be
counted as migrated pages and those vram pages should not be counted
as migrated pages. Here migration pages refer to how many vram pages
invloved. Current svm_migrate_unsuccessful_pages only covers the
unsuccessful case that source is on RAM.

So far, we only see two unsuccessful migration cases. Since we
can clearly identify successful migration cases through dst
MIGRATE_PFN_VALID bit and src MIGRATE_PFN_MIGRATE bit within this
prange, also eventually successful migration pages will be used,
so we can use function svm_migrate_successful_pages to replace
function svm_migrate_unsuccessful_pages.

Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Philip Yang<Philip.Yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index f0eb4547318a22c3382b145d4b15065175c4dc4a..d10c6673f4de4009979e034f7a2632270a6220fc 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -260,17 +260,17 @@ static void svm_migrate_put_sys_page(unsigned long addr)
        put_page(page);
 }
 
-static unsigned long svm_migrate_unsuccessful_pages(struct migrate_vma *migrate)
+static unsigned long svm_migrate_successful_pages(struct migrate_vma *migrate)
 {
-       unsigned long upages = 0;
+       unsigned long mpages = 0;
        unsigned long i;
 
        for (i = 0; i < migrate->npages; i++) {
-               if (migrate->src[i] & MIGRATE_PFN_VALID &&
-                   !(migrate->src[i] & MIGRATE_PFN_MIGRATE))
-                       upages++;
+               if (migrate->dst[i] & MIGRATE_PFN_VALID &&
+                   migrate->src[i] & MIGRATE_PFN_MIGRATE)
+                       mpages++;
        }
-       return upages;
+       return mpages;
 }
 
 static int
@@ -447,8 +447,8 @@ svm_migrate_vma_to_vram(struct kfd_node *node, struct svm_range *prange,
        svm_migrate_copy_done(adev, mfence);
        migrate_vma_finalize(&migrate);
 
-       mpages = cpages - svm_migrate_unsuccessful_pages(&migrate);
-       pr_debug("successful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
+       mpages = svm_migrate_successful_pages(&migrate);
+       pr_debug("migrated/collected/requested 0x%lx/0x%lx/0x%lx\n",
                 mpages, cpages, migrate.npages);
 
        svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
@@ -688,7 +688,6 @@ svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
 {
        struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
        u64 npages = (end - start) >> PAGE_SHIFT;
-       unsigned long upages = npages;
        unsigned long cpages = 0;
        unsigned long mpages = 0;
        struct amdgpu_device *adev = node->adev;
@@ -748,9 +747,9 @@ svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
                                    scratch, npages);
        migrate_vma_pages(&migrate);
 
-       upages = svm_migrate_unsuccessful_pages(&migrate);
-       pr_debug("unsuccessful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
-                upages, cpages, migrate.npages);
+       mpages = svm_migrate_successful_pages(&migrate);
+       pr_debug("migrated/collected/requested 0x%lx/0x%lx/0x%lx\n",
+                mpages, cpages, migrate.npages);
 
        svm_migrate_copy_done(adev, mfence);
        migrate_vma_finalize(&migrate);
@@ -763,8 +762,7 @@ out_free:
                                    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
                                    node->id, 0, trigger, r);
 out:
-       if (!r && cpages) {
-               mpages = cpages - upages;
+       if (!r && mpages) {
                pdd = svm_range_get_pdd_by_node(prange, node);
                if (pdd)
                        WRITE_ONCE(pdd->page_out, pdd->page_out + mpages);
@@ -847,6 +845,9 @@ int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm,
        }
 
        if (r >= 0) {
+               WARN_ONCE(prange->vram_pages < mpages,
+                         "Recorded vram pages(0x%llx) should not be less than migration pages(0x%lx).",
+                         prange->vram_pages, mpages);
                prange->vram_pages -= mpages;
 
                /* prange does not have vram page set its actual_loc to system