Hello, On Tue, Feb 21, 2023 at 04:43:44PM -0500, Peter Xu wrote: > If memory charge failed, the caller shouldn't call mem_cgroup_uncharge(). > Let alloc_charge_hpage() handle the error itself and clear hpage properly > if mem charge fails. I'm a bit confused by this patch. There isn't anything wrong with calling mem_cgroup_uncharge() on an uncharged page, functionally. It checks and bails out. It's an unnecessary call of course, but since it's an error path it's also not a cost issue, either. I could see an argument for improving the code, but this is actually more code, and the caller still has the uncharge-and-put branch anyway for when the collapse fails later on. So I'm not sure I understand the benefit of this change.
