Re: [External] Re: [PATCH v9 1/2] memory tier: dax/kmem: introduce an abstract layer for finding, allocating, and putting memory types

[Ho-Ren (Jack) Chuang]

Hi SeongJae,

On Mon, Apr 1, 2024 at 11:27 AM Ho-Ren (Jack) Chuang
<horenchuang@xxxxxxxxxxxxx> wrote:
>
> Hi SeongJae,
>
> On Sun, Mar 31, 2024 at 12:09 PM SeongJae Park <sj@xxxxxxxxxx> wrote:
> >
> > Hi Ho-Ren,
> >
> > On Fri, 29 Mar 2024 05:33:52 +0000 "Ho-Ren (Jack) Chuang" <horenchuang@xxxxxxxxxxxxx> wrote:
> >
> > > Since different memory devices require finding, allocating, and putting
> > > memory types, these common steps are abstracted in this patch,
> > > enhancing the scalability and conciseness of the code.
> > >
> > > Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@xxxxxxxxxxxxx>
> > > Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
> > > ---
> > >  drivers/dax/kmem.c           | 20 ++------------------
> > >  include/linux/memory-tiers.h | 13 +++++++++++++
> > >  mm/memory-tiers.c            | 32 ++++++++++++++++++++++++++++++++
> > >  3 files changed, 47 insertions(+), 18 deletions(-)
> > >
> > [...]
> > > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
> > > index 69e781900082..a44c03c2ba3a 100644
> > > --- a/include/linux/memory-tiers.h
> > > +++ b/include/linux/memory-tiers.h
> > > @@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist);
> > >  int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
> > >                            const char *source);
> > >  int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
> > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist,
> > > +                                                     struct list_head *memory_types);
> > > +void mt_put_memory_types(struct list_head *memory_types);
> > >  #ifdef CONFIG_MIGRATION
> > >  int next_demotion_node(int node);
> > >  void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
> > > @@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis
> > >  {
> > >       return -EIO;
> > >  }
> > > +
> > > +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
> > > +{
> > > +     return NULL;
> > > +}
> > > +
> > > +void mt_put_memory_types(struct list_head *memory_types)
> > > +{
> > > +
> > > +}
> >
> > I found latest mm-unstable tree is failing kunit as below, and 'git bisect'
> > says it happens from this patch.
> >
> >     $ ./tools/testing/kunit/kunit.py run --build_dir ../kunit.out/
> >     [11:56:40] Configuring KUnit Kernel ...
> >     [11:56:40] Building KUnit Kernel ...
> >     Populating config with:
> >     $ make ARCH=um O=../kunit.out/ olddefconfig
> >     Building with:
> >     $ make ARCH=um O=../kunit.out/ --jobs=36
> >     ERROR:root:In file included from .../mm/memory.c:71:
> >     .../include/linux/memory-tiers.h:143:25: warning: no previous prototype for ‘mt_find_alloc_memory_type’ [-Wmissing-prototypes]
> >       143 | struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
> >           |                         ^~~~~~~~~~~~~~~~~~~~~~~~~
> >     .../include/linux/memory-tiers.h:148:6: warning: no previous prototype for ‘mt_put_memory_types’ [-Wmissing-prototypes]
> >       148 | void mt_put_memory_types(struct list_head *memory_types)
> >           |      ^~~~~~~~~~~~~~~~~~~
> >     [...]
> >
> > Maybe we should set these as 'static inline', like below?  I confirmed this
> > fixes the kunit error.  May I ask your opinion?
> >
>
> Thanks for catching this. I'm trying to figure out this problem. Will get back.
>

These kunit compilation errors can be solved by adding `static inline`
to the two complaining functions, the same solution you mentioned
earlier.

I've also tested on my end and I will send out a V10 soon. Thank you again!

> >
> > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
> > index a44c03c2ba3a..ee6e53144156 100644
> > --- a/include/linux/memory-tiers.h
> > +++ b/include/linux/memory-tiers.h
> > @@ -140,12 +140,12 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis
> >         return -EIO;
> >  }
> >
> > -struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
> > +static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
> >  {
> >         return NULL;
> >  }
> >
> > -void mt_put_memory_types(struct list_head *memory_types)
> > +static inline void mt_put_memory_types(struct list_head *memory_types)
> >  {
> >
> >  }
> >
> >
> > Thanks,
> > SJ
>
>
>
> --
> Best regards,
> Ho-Ren (Jack) Chuang
> 莊賀任



-- 
Best regards,
Ho-Ren (Jack) Chuang
莊賀任