On Fri, 27 Oct 2023, Maciej Wieczór-Retman wrote:
> On 2023-10-24 at 12:26:12 +0300, Ilpo Järvinen wrote:
> >There are unnecessary nested calls in fill_buf.c:
> > - run_fill_buf() calls fill_cache()
> > - alloc_buffer() calls malloc_and_init_memory()
> >
> >Simplify the code flow and remove those unnecessary call levels by
> >moving the called code inside the calling function.
> >
> >Resolve the difference in run_fill_buf() and fill_cache() parameter
> >name into 'buf_size' which is more descriptive than 'span'.
> >
> >Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> >---
> > tools/testing/selftests/resctrl/fill_buf.c | 58 +++++++---------------
> > tools/testing/selftests/resctrl/resctrl.h | 2 +-
> > 2 files changed, 20 insertions(+), 40 deletions(-)
> >
> >diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c
> >index f9893edda869..9d0b0bf4b85a 100644
> >--- a/tools/testing/selftests/resctrl/fill_buf.c
> >+++ b/tools/testing/selftests/resctrl/fill_buf.c
> >@@ -51,29 +51,6 @@ static void mem_flush(unsigned char *buf, size_t buf_size)
> > sb();
> > }
> >
> >-static void *malloc_and_init_memory(size_t buf_size)
> >-{
> >- void *p = NULL;
> >- uint64_t *p64;
> >- size_t s64;
> >- int ret;
> >-
> >- ret = posix_memalign(&p, PAGE_SIZE, buf_size);
> >- if (ret < 0)
> >- return NULL;
> >-
> >- p64 = (uint64_t *)p;
> >- s64 = buf_size / sizeof(uint64_t);
> >-
> >- while (s64 > 0) {
> >- *p64 = (uint64_t)rand();
> >- p64 += (CL_SIZE / sizeof(uint64_t));
> >- s64 -= (CL_SIZE / sizeof(uint64_t));
> >- }
> >-
> >- return p;
> >-}
> >-
> > static int fill_one_span_read(unsigned char *buf, size_t buf_size)
> > {
> > unsigned char *end_ptr = buf + buf_size;
> >@@ -137,20 +114,33 @@ static int fill_cache_write(unsigned char *buf, size_t buf_size, bool once)
> >
> > static unsigned char *alloc_buffer(size_t buf_size, int memflush)
> > {
> >- unsigned char *buf;
> >+ void *p = NULL;
>
> Is this initialization doing anything? "p" seems to be either overwritten or in
> case of an error never accessed.
I'm aware of that but the compiler is too stupid to know that p is
initialized if there's no error and spits out a warning so I'll have to
keep the unnecessary initialization.
> >+ uint64_t *p64;
> >+ size_t s64;
> >+ int ret;
> >
> >- buf = malloc_and_init_memory(buf_size);
> >- if (!buf)
> >+ ret = posix_memalign(&p, PAGE_SIZE, buf_size);
> >+ if (ret < 0)
> > return NULL;
> >
> >+ /* Initialize the buffer */
> >+ p64 = (uint64_t *)p;
> >+ s64 = buf_size / sizeof(uint64_t);
> >+
> >+ while (s64 > 0) {
> >+ *p64 = (uint64_t)rand();
> >+ p64 += (CL_SIZE / sizeof(uint64_t));
> >+ s64 -= (CL_SIZE / sizeof(uint64_t));
> >+ }
> >+
> > /* Flush the memory before using to avoid "cache hot pages" effect */
> > if (memflush)
> >- mem_flush(buf, buf_size);
> >+ mem_flush(p, buf_size);
>
> Wouldn't renaming "p" to "buf" keep this relationship with "buf_size" more
> explicit?
I'll change it to buf. This patch has a long history which preceeds the
change where I made the buffer ptr naming more consistent and I didn't
realize I departed here again from the consistent naming until you now
pointed it out.
--
i.
