bus/dpaa: optimize device name parsing
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Commit Message
Device name parsing is done on all buses during device iterations at
either EAL or ethdev levels.
When a bus implements device name parsing slowly, all iterations are
impacted. Efficient implementation is important.
The DPAA bus device name parsing has two issues: it allocates dynamic
memory and uses snprintf without a real need for it. Both can be
avoided, which improves the parsing performance.
The function is also simpler and shorter.
Signed-off-by: Gaetan Rivet <grive@u256.net>
---
drivers/bus/dpaa/dpaa_bus.c | 69 +++++++++++++++----------------------
1 file changed, 27 insertions(+), 42 deletions(-)
Comments
On 09/11/20 12:31 +0100, Gaetan Rivet wrote:
> Device name parsing is done on all buses during device iterations at
> either EAL or ethdev levels.
>
> When a bus implements device name parsing slowly, all iterations are
> impacted. Efficient implementation is important.
>
> The DPAA bus device name parsing has two issues: it allocates dynamic
> memory and uses snprintf without a real need for it. Both can be
> avoided, which improves the parsing performance.
>
> The function is also simpler and shorter.
>
> Signed-off-by: Gaetan Rivet <grive@u256.net>
> ---
Sorry I meant to annotate this patch before sending.
Please note that I could not test with a real DPAA bus. There are some
string offsets that should be correct but the parsing still needs to
be tested.
Cheers,
On Mon, Nov 9, 2020 at 12:32 PM Gaetan Rivet <grive@u256.net> wrote:
> + delta = 0;
> + if (strncmp(name, "dpaa_bus:", 9) == 0) {
> + delta = 9;
> + } else if (strncmp(name, "name=", 5) == 0) {
> + delta = 5;
> + }
> +
> + if (sscanf(&name[delta], "fm%u-mac%u", &i, &j) == 2) {
> + if (i >= 2 || j >= 16)
> + return -EINVAL;
> + if (out != NULL) {
> + char *out_name = out;
> +
> + if (rte_strscpy(out_name, &name[delta], 10) < 0)
> + return -ENAMETOOLONG;
> + /* Because 'i' can only be 0 or 1, fm%u is fixed size ;
> + * mac%u needs to be checked for optional end ','.
> + */
> + if (out_name[9] == ',')
> + out_name[9] = '\0';
> }
> + return 0;
> + } else {
> + return -EINVAL;
> }
Mmm, we always return from each of the previous branches?
Then the ENODEV return after is dead code.
Reading again the diff, you could probably return at the sscanf step.
if (sscanf(&name[delta], "fm%u-mac%u", &i, &j) != 2 || i >= 2 || j >= 16)
return -EINVAL;
>
> - free(dup_name);
> - return -EINVAL;
> + return -ENODEV;
> }
>
> #define DPAA_DEV_PATH1 "/sys/devices/platform/soc/soc:fsl,dpaa"
On 09/11/20 12:58 +0100, David Marchand wrote:
> On Mon, Nov 9, 2020 at 12:32 PM Gaetan Rivet <grive@u256.net> wrote:
> > + delta = 0;
> > + if (strncmp(name, "dpaa_bus:", 9) == 0) {
> > + delta = 9;
> > + } else if (strncmp(name, "name=", 5) == 0) {
> > + delta = 5;
> > + }
> > +
> > + if (sscanf(&name[delta], "fm%u-mac%u", &i, &j) == 2) {
> > + if (i >= 2 || j >= 16)
> > + return -EINVAL;
> > + if (out != NULL) {
> > + char *out_name = out;
> > +
> > + if (rte_strscpy(out_name, &name[delta], 10) < 0)
> > + return -ENAMETOOLONG;
> > + /* Because 'i' can only be 0 or 1, fm%u is fixed size ;
> > + * mac%u needs to be checked for optional end ','.
> > + */
> > + if (out_name[9] == ',')
> > + out_name[9] = '\0';
> > }
> > + return 0;
> > + } else {
> > + return -EINVAL;
> > }
>
> Mmm, we always return from each of the previous branches?
> Then the ENODEV return after is dead code.
>
> Reading again the diff, you could probably return at the sscanf step.
> if (sscanf(&name[delta], "fm%u-mac%u", &i, &j) != 2 || i >= 2 || j >= 16)
> return -EINVAL;
>
>
Yes good point, I will refactor.
> >
> > - free(dup_name);
> > - return -EINVAL;
> > + return -ENODEV;
> > }
> >
> > #define DPAA_DEV_PATH1 "/sys/devices/platform/soc/soc:fsl,dpaa"
>
>
> --
> David Marchand
>
@@ -385,12 +385,10 @@ dpaa_portal_finish(void *arg)
}
static int
-rte_dpaa_bus_parse(const char *name, void *out_name)
+rte_dpaa_bus_parse(const char *name, void *out)
{
- int i, j;
- int max_fman = 2, max_macs = 16;
- char *dup_name;
- char *sep = NULL;
+ unsigned int i, j;
+ size_t delta;
/* There are two ways of passing device name, with and without
* separator. "dpaa_bus:fm1-mac3" with separator, and "fm1-mac3"
@@ -399,46 +397,33 @@ rte_dpaa_bus_parse(const char *name, void *out_name)
*/
DPAA_BUS_DEBUG("Parse device name (%s)", name);
- /* Check for dpaa_bus:fm1-mac3 style */
- dup_name = strdup(name);
- sep = strchr(dup_name, ':');
- if (!sep)
- /* If not, check for name=fm1-mac3 style */
- sep = strchr(dup_name, '=');
-
- if (sep)
- /* jump over the seprator */
- sep = (char *) (sep + 1);
- else
- sep = dup_name;
-
- for (i = 0; i < max_fman; i++) {
- for (j = 0; j < max_macs; j++) {
- char fm_name[16];
- snprintf(fm_name, 16, "fm%d-mac%d", i, j);
- if (strcmp(fm_name, sep) == 0) {
- if (out_name)
- strcpy(out_name, sep);
- free(dup_name);
- return 0;
- }
- }
- }
-
- for (i = 0; i < RTE_LIBRTE_DPAA_MAX_CRYPTODEV; i++) {
- char sec_name[16];
-
- snprintf(sec_name, 16, "dpaa_sec-%d", i+1);
- if (strcmp(sec_name, sep) == 0) {
- if (out_name)
- strcpy(out_name, sep);
- free(dup_name);
- return 0;
+ delta = 0;
+ if (strncmp(name, "dpaa_bus:", 9) == 0) {
+ delta = 9;
+ } else if (strncmp(name, "name=", 5) == 0) {
+ delta = 5;
+ }
+
+ if (sscanf(&name[delta], "fm%u-mac%u", &i, &j) == 2) {
+ if (i >= 2 || j >= 16)
+ return -EINVAL;
+ if (out != NULL) {
+ char *out_name = out;
+
+ if (rte_strscpy(out_name, &name[delta], 10) < 0)
+ return -ENAMETOOLONG;
+ /* Because 'i' can only be 0 or 1, fm%u is fixed size ;
+ * mac%u needs to be checked for optional end ','.
+ */
+ if (out_name[9] == ',')
+ out_name[9] = '\0';
}
+ return 0;
+ } else {
+ return -EINVAL;
}
- free(dup_name);
- return -EINVAL;
+ return -ENODEV;
}
#define DPAA_DEV_PATH1 "/sys/devices/platform/soc/soc:fsl,dpaa"