On Fri, Oct 20, 2023 at 10:58:37AM -0700, Alexei Starovoitov wrote: > On Fri, Oct 20, 2023 at 10:48 AM Dennis Zhou <dennis@xxxxxxxxxx> wrote: > > > > On Fri, Oct 20, 2023 at 09:31:57PM +0800, Hou Tao wrote: > > > From: Hou Tao <houtao1@xxxxxxxxxx> > > > > > > Introduce pcpu_alloc_size() to get the size of the dynamic per-cpu > > > area. It will be used by bpf memory allocator in the following patches. > > > BPF memory allocator maintains per-cpu area caches for multiple area > > > sizes and its free API only has the to-be-freed per-cpu pointer, so it > > > needs the size of dynamic per-cpu area to select the corresponding cache > > > when bpf program frees the dynamic per-cpu pointer. > > > > > > Acked-by: Dennis Zhou <dennis@xxxxxxxxxx> > > > Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx> > > > --- > > > include/linux/percpu.h | 1 + > > > mm/percpu.c | 31 +++++++++++++++++++++++++++++++ > > > 2 files changed, 32 insertions(+) > > > > > > diff --git a/include/linux/percpu.h b/include/linux/percpu.h > > > index 68fac2e7cbe67..8c677f185901b 100644 > > > --- a/include/linux/percpu.h > > > +++ b/include/linux/percpu.h > > > @@ -132,6 +132,7 @@ extern void __init setup_per_cpu_areas(void); > > > extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); > > > extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); > > > extern void free_percpu(void __percpu *__pdata); > > > +extern size_t pcpu_alloc_size(void __percpu *__pdata); > > > > > > DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T)) > > > > > > diff --git a/mm/percpu.c b/mm/percpu.c > > > index 76b9c5e63c562..1759b91c8944a 100644 > > > --- a/mm/percpu.c > > > +++ b/mm/percpu.c > > > @@ -2244,6 +2244,37 @@ static void pcpu_balance_workfn(struct work_struct *work) > > > mutex_unlock(&pcpu_alloc_mutex); > > > } > > > > > > +/** > > > + * pcpu_alloc_size - the size of the dynamic percpu area > > > + * @ptr: pointer to the dynamic percpu area > > > + * > > > + * Returns the size of the @ptr allocation. This is undefined for statically > > ^ > > > > Nit: Alexei, when you pull this, can you make it a double space here? > > Just keeps percpu's file consistent. > > Argh. Already applied. > That's a very weird style you have in a few places. > $ grep '\. [A-z]' mm/*.c|wc -l > 1118 > $ grep '\. [A-z]' mm/*.c|wc -l > 2451 > > Single space is used more often in mm/* and in the rest of the kernel. > > $ grep '\. [A-z]' mm/percpu.c|wc -l > 10 > > percpu.c isn't consistent either. > > I can force push if you really insist. Eh, if it's trouble I can fix it in the future. I know single space is more common, but percpu was written with double so I'm trying my best to keep the file consistent. Thanks, Dennis
