On Tue, Dec 17, 2024 at 10:37 PM Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Tue, Dec 17, 2024 at 9:58 PM Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > > > > What I mean is, functions like __free_unref_page() and > > free_unref_page_commit() now accept fpi_flags, but any flags other > > than FPI_TRYLOCK are essentially ignored, also not very clear. > > They're not ignored. They are just not useful in this context. I think they are. For example, if you pass FPI_SKIP_REPORT_NOTIFY to __free_unref_page(), page_reporting_notify_free() will still be called when the page is eventually freed to the buddy allocator. Same goes for FPI_NO_TAIL. > The code rules over comment. If you have a concrete suggestion on > how to improve the comment please say so. What I had in mind is adding a WARN in the pcp freeing functions if any FPI flag but FPI_TRYLOCK is passed, and/or explicitly calling out that other flags should not be passed as they have no effect in this context (whether at the function definition, above the WARN, or at the flag definitions).