Re: [PATCH v4 2/2] rust: add system_percpu() and per-cpu enqueue functions

[kernel test robot]

Hi Marco,

kernel test robot noticed the following build errors:

[auto build test ERROR on rust/rust-next]
[also build test ERROR on linus/master v6.19-rc8 next-20260203]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Marco-Crivellari/rust-add-system_dfl-around-the-new-system_dfl_wq/20260203-233415
base:   https://github.com/Rust-for-Linux/linux rust-next
patch link:    https://lore.kernel.org/r/20260203152818.317806-3-marco.crivellari%40suse.com
patch subject: [PATCH v4 2/2] rust: add system_percpu() and per-cpu enqueue functions
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260204/202602040208.hNcu9QEl-lkp@xxxxxxxxx/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260204/202602040208.hNcu9QEl-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602040208.hNcu9QEl-lkp@xxxxxxxxx/

All error/warnings (new ones prefixed by >>):

   PATH=/opt/cross/clang-20/bin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
   INFO PATH=/opt/cross/rustc-1.88.0-bindgen-0.72.1/cargo/bin:/opt/cross/clang-20/bin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
   /usr/bin/timeout -k 100 12h /usr/bin/make KCFLAGS= -fno-crash-diagnostics -Wno-error=return-type -Wreturn-type -funsigned-char -Wundef -falign-functions=64 W=1 --keep-going LLVM=1 -j32 -C source O=/kbuild/obj/consumer/x86_64-rhel-9.4-rust ARCH=x86_64 SHELL=/bin/bash rustfmtcheck
   make: Entering directory '/kbuild/src/consumer'
   make[1]: Entering directory '/kbuild/obj/consumer/x86_64-rhel-9.4-rust'
>> Diff in rust/kernel/workqueue.rs:316:
            // stay valid until we call the function pointer in the `work_struct`, so the access is ok.
            unsafe {
                w.__enqueue(move |work_ptr| {
   -                bindings::queue_work_on(
   -                    cpu_id as ffi::c_int,
   -                    queue_ptr,
   -                    work_ptr,
   -                )
   +                bindings::queue_work_on(cpu_id as ffi::c_int, queue_ptr, work_ptr)
                })
            }
        }
   Diff in rust/kernel/workqueue.rs:366:
        /// This may fail if the work item is already enqueued in a workqueue.
        ///
        /// The work item will be submitted on cpu_id.
   -    pub fn enqueue_delayed_cpu<W, const ID: u64>(&self, w: W, delay: Jiffies, cpu_id: u32) -> W::EnqueueOutput
   +    pub fn enqueue_delayed_cpu<W, const ID: u64>(
   +        &self,
   +        w: W,
   +        delay: Jiffies,
   +        cpu_id: u32,
   +    ) -> W::EnqueueOutput
        where
            W: RawDelayedWorkItem<ID> + Send + 'static,
        {
>> Diff in rust/kernel/workqueue.rs:316:
            // stay valid until we call the function pointer in the `work_struct`, so the access is ok.
            unsafe {
                w.__enqueue(move |work_ptr| {
   -                bindings::queue_work_on(
   -                    cpu_id as ffi::c_int,
   -                    queue_ptr,
   -                    work_ptr,
   -                )
   +                bindings::queue_work_on(cpu_id as ffi::c_int, queue_ptr, work_ptr)
                })
            }
        }
   Diff in rust/kernel/workqueue.rs:366:
        /// This may fail if the work item is already enqueued in a workqueue.
        ///
        /// The work item will be submitted on cpu_id.
   -    pub fn enqueue_delayed_cpu<W, const ID: u64>(&self, w: W, delay: Jiffies, cpu_id: u32) -> W::EnqueueOutput
   +    pub fn enqueue_delayed_cpu<W, const ID: u64>(
   +        &self,
   +        w: W,
   +        delay: Jiffies,
   +        cpu_id: u32,
   +    ) -> W::EnqueueOutput
        where
            W: RawDelayedWorkItem<ID> + Send + 'static,
        {
   make[2]: *** [Makefile:1871: rustfmt] Error 123
   make[2]: Target 'rustfmtcheck' not remade because of errors.
   make[1]: Leaving directory '/kbuild/obj/consumer/x86_64-rhel-9.4-rust'
   make[1]: *** [Makefile:248: __sub-make] Error 2
   make[1]: Target 'rustfmtcheck' not remade because of errors.
   make: *** [Makefile:248: __sub-make] Error 2
   make: Target 'rustfmtcheck' not remade because of errors.
   make: Leaving directory '/kbuild/src/consumer'
--
>> warning: unresolved link to `system_percpu_wq`
   --> rust/kernel/workqueue.rs:1013:72
   |
   1013 | /// Note: `system_wq` will be removed in a future release cycle. Use [`system_percpu_wq`] instead.
   |                                                                        ^^^^^^^^^^^^^^^^ no item named `system_percpu_wq` in scope
   |
   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
   = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

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