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charset=us-ascii Content-Disposition: inline In-Reply-To: <20231018113343.2446300-3-houtao@huaweicloud.com> X-Rspamd-Queue-Id: DCBCC40012 X-Rspam-User: X-Stat-Signature: cw9w8r6sb3gba6dnki4qk6ch6x3hgdty X-Rspamd-Server: rspam01 X-HE-Tag: 1697774967-236484 X-HE-Meta: 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 RJKXOUv+ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Oct 18, 2023 at 07:33:38PM +0800, Hou Tao wrote: > From: Hou Tao > > 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. > > Signed-off-by: Hou Tao > --- > include/linux/percpu.h | 1 + > mm/percpu.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 31 insertions(+) > > diff --git a/include/linux/percpu.h b/include/linux/percpu.h > index 68fac2e7cbe6..8c677f185901 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 76b9c5e63c56..b0cea2dc16a9 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -2244,6 +2244,36 @@ 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 > + * > + * Return the size of the dynamic percpu area @ptr. > + * Alexei, can you modify the above comment to: Returns the size of the @ptr allocation. This is undefined for statically defined percpu variables as there is no corresponding chunk->bound_map. > + * RETURNS: > + * The size of the dynamic percpu area. > + * > + * CONTEXT: > + * Can be called from atomic context. > + */ > +size_t pcpu_alloc_size(void __percpu *ptr) > +{ > + struct pcpu_chunk *chunk; > + unsigned long bit_off, end; > + void *addr; > + > + if (!ptr) > + return 0; > + > + addr = __pcpu_ptr_to_addr(ptr); > + /* No pcpu_lock here: ptr has not been freed, so chunk is still alive */ > + chunk = pcpu_chunk_addr_search(addr); > + bit_off = (addr - chunk->base_addr) / PCPU_MIN_ALLOC_SIZE; > + end = find_next_bit(chunk->bound_map, pcpu_chunk_map_bits(chunk), > + bit_off + 1); > + return (end - bit_off) * PCPU_MIN_ALLOC_SIZE; > +} > + > /** > * free_percpu - free percpu area > * @ptr: pointer to area to free > -- > 2.29.2 > > Acked-by: Dennis Zhou Thanks, Dennis