[RFC 2/2] io_uring: report pinned memory usage

[Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx>]

Long term, it makes sense to separate reporting and enforcing of pinned
memory usage.

Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx>

It is useful to view
---
 fs/io_uring.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4248726..cf3acaa 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7080,6 +7080,8 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
 static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages)
 {
 	atomic_long_sub(nr_pages, &user->locked_vm);
+	if (current->mm)
+		atomic_long_sub(nr_pages, &current->mm->pinned_vm);
 }
 
 static int io_account_mem(struct user_struct *user, unsigned long nr_pages)
@@ -7096,6 +7098,8 @@ static int io_account_mem(struct user_struct *user, unsigned long nr_pages)
 			return -ENOMEM;
 	} while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
 					new_pages) != cur_pages);
+	if (current->mm)
+		atomic_long_add(nr_pages, &current->mm->pinned_vm);
 
 	return 0;
 }
-- 
1.8.3.1