Messages in this thread | | | Date | Mon, 20 Jun 2022 17:36:47 -0400 | From | Qian Cai <> | Subject | Re: [PATCH v2 2/3] mm/swapfile: fix possible data races of inuse_pages |
| |
On Mon, Jun 20, 2022 at 10:20:07PM +0800, Muchun Song wrote: > The lock does not protect the read sides. So the write side should be > fixed by WRITTE_ONCE().
https://lwn.net/Articles/816854/
"Unmarked writes (aligned and up to word size) can be treated as if they had used WRITE_ONCE() by building with CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=y (also selected by default). Experience has shown that compilers are much less likely to destructively optimize in-kernel writes than reads. Some developers might therefore choose to use READ_ONCE() but omit the corresponding WRITE_ONCE(). Other developers might prefer the documentation benefits and long-term peace of mind accruing from explicit use of WRITE_ONCE()..."
| |