Messages in this thread | | | Date | Wed, 4 Jul 2018 15:36:17 +0000 | From | Dmitry Torokhov <> | Subject | Re: [PATCH 2/2] bitmap: sync tools with new bitmap allocation API |
| |
On Mon, Jun 25, 2018 at 01:45:22AM +0300, Yury Norov wrote: > On Sun, Jun 24, 2018 at 02:31:03PM -0700, Dmitry Torokhov wrote: > > External Email > > > > On Sat, Jun 23, 2018 at 10:35:02AM +0300, Yury Norov wrote: > > > On top of next-20180622 and Andy Shevchenko series: > > > https://lkml.org/lkml/2018/6/18/841 > > > > > > The series mentioned above introduces helpers for bitmap allocation. > > > tools/ has its own bitmap_alloc() which differs from bitmap_alloc() > > > proposed in new kernel API, and is equivalent to bitmap_zalloc(). > > > In this series tools is switched to new API. > > > > > > This is RFC because I didn't find counterpart free() call to some > > > bitmap_zalloc()'s. So I didn't convert them to bitmap_free(). Could > > > someone point me out? The functions are: > > > setup_nodes(); > > > do_read_bitmap(); // Free is called, but only in fail path. > > > > Yes, because if we succeed we effectively return allocated bitmap to the > > caller. You'd need to trace upwards and see how it all gets cleaned up. > > But given that this is userspace and is not expected to be long-lived, > > maybe nobody bothered freeing memory and we instead rely on the kernel > > to clean it all up when process terminates. > > > > Thanks. > > > > > memory_node__read(); > > > > > > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> > > > --- > > > tools/include/linux/bitmap.h | 19 +++++++++++++++---- > > > tools/perf/builtin-c2c.c | 10 +++++----- > > > tools/perf/tests/bitmap.c | 4 ++-- > > > tools/perf/tests/mem2node.c | 4 ++-- > > > tools/perf/util/header.c | 6 +++--- > > > 5 files changed, 27 insertions(+), 16 deletions(-) > > > > > > diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h > > > index 48c208437bbd..b9b85b94c937 100644 > > > --- a/tools/include/linux/bitmap.h > > > +++ b/tools/include/linux/bitmap.h > > > @@ -98,12 +98,23 @@ static inline int test_and_set_bit(int nr, unsigned long *addr) > > > } > > > > > > /** > > > - * bitmap_alloc - Allocate bitmap > > > - * @nbits: Number of bits > > > + * Allocation and deallocation of bitmap. > > > */ > > > -static inline unsigned long *bitmap_alloc(int nbits) > > > +static inline unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) > > > > This makes absolutely no sense for userspace API. What gfp_t even means > > here? > > > > If you want to introduce bitmap_zalloc and bitmap_free it is fine but > > adding dummy parameters to match kernel API exactly is a folly. > > Identical API makes easier porting the code from kernel to tools. > Refer for example declaration of kmalloc in: > tools/testing/radix-tree/linux.c > tools/testing/scatterlist/linux/mm.h > tools/virtio/linux/kernel.h > tools/virtio/ringtest/ptr_ring.c
These are unittests for the APIs in question, of course they would have to match exactly.
perf tool however is not a unittest, so there is no need to match kernel API.
Thanks.
-- Dmitry
| |