[dpdk-dev] [PATCH 2/3] trace: remove size limit on CTF event description
Jerin Jacob
jerinjacobk at gmail.com
Wed Oct 28 10:06:20 CET 2020
On Fri, Oct 23, 2020 at 1:32 PM David Marchand
<david.marchand at redhat.com> wrote:
>
> Rework registration so that it uses dynamic allocations and has no size
> limit.
>
> Signed-off-by: David Marchand <david.marchand at redhat.com>
Reviewed-by: Jerin Jacob <jerinj at marvell.com>
> ---
> lib/librte_eal/common/eal_common_trace.c | 39 +++++++++-----------
> lib/librte_eal/common/eal_common_trace_ctf.c | 3 +-
> lib/librte_eal/common/eal_trace.h | 3 +-
> 3 files changed, 20 insertions(+), 25 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_common_trace.c b/lib/librte_eal/common/eal_common_trace.c
> index 80b458edb6..bc031ca719 100644
> --- a/lib/librte_eal/common/eal_common_trace.c
> +++ b/lib/librte_eal/common/eal_common_trace.c
> @@ -17,8 +17,7 @@
>
> RTE_DEFINE_PER_LCORE(volatile int, trace_point_sz);
> RTE_DEFINE_PER_LCORE(void *, trace_mem);
> -static RTE_DEFINE_PER_LCORE(char, ctf_field[TRACE_CTF_FIELD_SIZE]);
> -static RTE_DEFINE_PER_LCORE(int, ctf_count);
> +static RTE_DEFINE_PER_LCORE(char *, ctf_field);
>
> static struct trace_point_head tp_list = STAILQ_HEAD_INITIALIZER(tp_list);
> static struct trace trace = { .args = STAILQ_HEAD_INITIALIZER(trace.args), };
> @@ -429,32 +428,33 @@ trace_mem_free(void)
> void
> __rte_trace_point_emit_field(size_t sz, const char *in, const char *datatype)
> {
> - char *field = RTE_PER_LCORE(ctf_field);
> - int count = RTE_PER_LCORE(ctf_count);
> - size_t size;
> + char *field;
> char *fixup;
> int rc;
>
> - size = RTE_MAX(0, TRACE_CTF_FIELD_SIZE - 1 - count);
> - RTE_PER_LCORE(trace_point_sz) += sz;
> fixup = trace_metadata_fixup_field(in);
> if (fixup != NULL)
> in = fixup;
> - rc = snprintf(RTE_PTR_ADD(field, count), size, "%s %s;", datatype, in);
> + rc = asprintf(&field, "%s%s %s;",
> + RTE_PER_LCORE(ctf_field) != NULL ?
> + RTE_PER_LCORE(ctf_field) : "",
> + datatype, in);
> + free(RTE_PER_LCORE(ctf_field));
> free(fixup);
> - if (rc <= 0 || (size_t)rc >= size) {
> + if (rc == -1) {
> RTE_PER_LCORE(trace_point_sz) = 0;
> - trace_crit("CTF field is too long");
> + RTE_PER_LCORE(ctf_field) = NULL;
> + trace_crit("could not allocate CTF field");
> return;
> }
> - RTE_PER_LCORE(ctf_count) += rc;
> + RTE_PER_LCORE(trace_point_sz) += sz;
> + RTE_PER_LCORE(ctf_field) = field;
> }
>
> int
> __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
> void (*register_fn)(void))
> {
> - char *field = RTE_PER_LCORE(ctf_field);
> struct trace_point *tp;
> uint16_t sz;
>
> @@ -467,7 +467,6 @@ __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
>
> /* Check the size of the trace point object */
> RTE_PER_LCORE(trace_point_sz) = 0;
> - RTE_PER_LCORE(ctf_count) = 0;
> register_fn();
> if (RTE_PER_LCORE(trace_point_sz) == 0) {
> trace_err("missing rte_trace_emit_header() in register fn");
> @@ -505,15 +504,11 @@ __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
> goto free;
> }
>
> - /* Copy the field data for future use */
> - if (rte_strscpy(tp->ctf_field, field, TRACE_CTF_FIELD_SIZE) < 0) {
> - trace_err("CTF field size is too long");
> - rte_errno = E2BIG;
> - goto free;
> - }
> -
> - /* Clear field memory for the next event */
> - memset(field, 0, TRACE_CTF_FIELD_SIZE);
> + /* Copy the accumulated fields description and clear it for the next
> + * trace point.
> + */
> + tp->ctf_field = RTE_PER_LCORE(ctf_field);
> + RTE_PER_LCORE(ctf_field) = NULL;
>
> /* Form the trace handle */
> *handle = sz;
> diff --git a/lib/librte_eal/common/eal_common_trace_ctf.c b/lib/librte_eal/common/eal_common_trace_ctf.c
> index bc86432902..884dd0fa4b 100644
> --- a/lib/librte_eal/common/eal_common_trace_ctf.c
> +++ b/lib/librte_eal/common/eal_common_trace_ctf.c
> @@ -233,7 +233,8 @@ meta_event_emit(char **meta, int *offset, struct trace_point *tp)
> " fields := struct {\n"
> " %s\n"
> " };\n"
> - "};\n\n", trace_id_get(tp->handle), tp->name, tp->ctf_field);
> + "};\n\n", trace_id_get(tp->handle), tp->name,
> + tp->ctf_field != NULL ? tp->ctf_field : "");
> return meta_copy(meta, offset, str, rc);
> }
>
> diff --git a/lib/librte_eal/common/eal_trace.h b/lib/librte_eal/common/eal_trace.h
> index 8a3f6c5359..06751eb23a 100644
> --- a/lib/librte_eal/common/eal_trace.h
> +++ b/lib/librte_eal/common/eal_trace.h
> @@ -24,7 +24,6 @@
>
> #define TRACE_PREFIX_LEN 12
> #define TRACE_DIR_STR_LEN (sizeof("YYYY-mm-dd-AM-HH-MM-SS") + TRACE_PREFIX_LEN)
> -#define TRACE_CTF_FIELD_SIZE 448
> #define TRACE_POINT_NAME_SIZE 64
> #define TRACE_CTF_MAGIC 0xC1FC1FC1
> #define TRACE_MAX_ARGS 32
> @@ -33,7 +32,7 @@ struct trace_point {
> STAILQ_ENTRY(trace_point) next;
> rte_trace_point_t *handle;
> char name[TRACE_POINT_NAME_SIZE];
> - char ctf_field[TRACE_CTF_FIELD_SIZE];
> + char *ctf_field;
> };
>
> enum trace_area_e {
> --
> 2.23.0
>
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