Re: [PATCH v4 08/14] ACPI: add perf low power callback

[Like Xu]

On 14/12/2021 6:40 am, kernel test robot wrote:
> Hi Stephane,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on tip/perf/core]
> [also build test ERROR on tip/x86/core v5.16-rc5]
> [cannot apply to rafael-pm/linux-next]
> [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]
>
> url:https://github.com/0day-ci/linux/commits/Stephane-Eranian/perf-x86-amd-Add-AMD-Fam19h-Branch-Sampling-support/20211211-050541
> base:https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git  a9f4a6e92b3b319296fb078da2615f618f6cd80c
> config: x86_64-randconfig-c002-20211210 (https://download.01.org/0day-ci/archive/20211214/202112140636.UOuRtBxF-lkp@xxxxxxxxx/config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
>          #https://github.com/0day-ci/linux/commit/9d928356688ed9c42e01fed16e59c1d6eda16647
>          git remote add linux-reviewhttps://github.com/0day-ci/linux
>          git fetch --no-tags linux-review Stephane-Eranian/perf-x86-amd-Add-AMD-Fam19h-Branch-Sampling-support/20211211-050541
>          git checkout 9d928356688ed9c42e01fed16e59c1d6eda16647
>          # save the config file to linux build tree
>          mkdir build_dir
>          make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot<lkp@xxxxxxxxx>
>
> All errors (new ones prefixed by >>):
>
>     drivers/acpi/acpi_pad.c: In function 'power_saving_thread':
> > > drivers/acpi/acpi_pad.c:168:4: error: implicit declaration of function 'perf_lopwr_cb' [-Werror=implicit-function-declaration]
>       168 |    perf_lopwr_cb(true);
>           |    ^~~~~~~~~~~~~
>     cc1: some warnings being treated as errors

Hi Stephane,

does this snippet help to fix this issue ?

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index a306a07a6..fdb505305 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <asm/mwait.h>
+#include <linux/perf_event.h>
 #include <xen/xen.h>

 #define ACPI_PROCESSOR_AGGREGATOR_CLASS        "acpi_pad"

What's more, it seems thet "CONFIG_ACPI_PROCESSOR_AGGREGATOR=y" is requested
for "CONFIG_PERF_EVENTS_AMD_BRS=y". Otherwise, we need to EXPORT_SYMBOL_GPL
for both perf_lopwr_needed and perf_amd_brs_lopwr_cb. Got a better idea?

Thanks,
Like Xu

> vim +/perf_lopwr_cb +168 drivers/acpi/acpi_pad.c