On 8/20/23 05:43, Matthew Brost wrote:
On Fri, Aug 18, 2023 at 05:08:44PM +0200, Thomas Hellström wrote:
Account these pages against RLIMIT_MEMLOCK following how RDMA does this
with CAP_IPC_LOCK bypassing the limit.
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Patch LGTM but nits on naming + possible assert.
---
drivers/gpu/drm/xe/xe_vm.c | 43 ++++++++++++++++++++++++++++++++++++--
1 file changed, 41 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index ecbcad696b60..d9c000689002 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -34,6 +34,33 @@
#define TEST_VM_ASYNC_OPS_ERROR
+/*
+ * Perform userptr PIN accounting against RLIMIT_MEMLOCK for now, similarly
+ * to how RDMA does this.
+ */
+static int xe_vma_mlock_alloc(struct xe_vma *vma, unsigned long num_pages)
+{
xe_vma_userptr_mlock_alloc? or maybe even xe_vma_userptr_mlock_reserve?
+ unsigned long lock_limit, new_pinned;
+ struct mm_struct *mm = vma->userptr.notifier.mm;
+
This be a candidate to use the new aseert macros to ensure that the vma
is a userptr + pinned? Not sure if that merged yet.
+ if (!can_do_mlock())
+ return -EPERM;
+
+ lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+ new_pinned = atomic64_add_return(num_pages, &mm->pinned_vm);
+ if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
+ atomic64_sub(num_pages, &mm->pinned_vm);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void xe_vma_mlock_free(struct xe_vma *vma, unsigned long num_pages)
+{
xe_vma_userptr_mlock_free? or maybe even xe_vma_userptr_mlock_release?
Same for the assert here.
Anyways, I'll leave addressing these nits up to you, with that:
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
OK, thanks. I'll take a look at addressing those.
+ atomic64_sub(num_pages, &vma->userptr.notifier.mm->pinned_vm);
+}
+
/**
* xe_vma_userptr_check_repin() - Advisory check for repin needed
* @vma: The userptr vma
@@ -89,9 +116,17 @@ int xe_vma_userptr_pin_pages(struct xe_vma *vma)
!read_only);
pages = vma->userptr.pinned_pages;
} else {
+ if (xe_vma_is_pinned(vma)) {
+ ret = xe_vma_mlock_alloc(vma, num_pages);
+ if (ret)
+ return ret;
+ }
+
pages = kvmalloc_array(num_pages, sizeof(*pages), GFP_KERNEL);
- if (!pages)
- return -ENOMEM;
+ if (!pages) {
+ ret = -ENOMEM;
+ goto out_account;
+ }
}
pinned = ret = 0;
@@ -187,6 +222,9 @@ int xe_vma_userptr_pin_pages(struct xe_vma *vma)
mm_closed:
kvfree(pages);
vma->userptr.pinned_pages = NULL;
+out_account:
+ if (xe_vma_is_pinned(vma))
+ xe_vma_mlock_free(vma, num_pages);
return ret;
}
@@ -1004,6 +1042,7 @@ static void xe_vma_destroy_late(struct xe_vma *vma)
unpin_user_pages_dirty_lock(vma->userptr.pinned_pages,
vma->userptr.num_pinned,
!read_only);
+ xe_vma_mlock_free(vma, xe_vma_size(vma) >> PAGE_SHIFT);
kvfree(vma->userptr.pinned_pages);
}
--
2.41.0
