[DTrace-devel] [PATCH] Free the DIFO for a probe once it is loaded
Kris Van Hees
kris.van.hees at oracle.com
Fri Jul 25 04:01:56 UTC 2025
When a lot of probes are being probed, keeping all DIFO around consumes
a lot of memory. Once the BPF program is loaded, the DIFO can be freed.
Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
libdtrace/dt_bpf.c | 23 ++++++++++++++++-------
libdtrace/dt_prov_uprobe.c | 22 +++++++++++++++-------
2 files changed, 31 insertions(+), 14 deletions(-)
diff --git a/libdtrace/dt_bpf.c b/libdtrace/dt_bpf.c
index ccec8b43..56b6b01d 100644
--- a/libdtrace/dt_bpf.c
+++ b/libdtrace/dt_bpf.c
@@ -1339,6 +1339,7 @@ dt_bpf_load_progs(dtrace_hdl_t *dtp, uint_t cflags)
*/
dtrace_getopt(dtp, "destructive", &dest_ok);
+ dp = NULL;
for (prp = dt_list_next(&dtp->dt_enablings); prp != NULL;
prp = dt_list_next(prp)) {
int fd;
@@ -1353,28 +1354,36 @@ dt_bpf_load_progs(dtrace_hdl_t *dtp, uint_t cflags)
continue;
if (dt_link(dtp, prp, dp, NULL) == -1)
- return -1;
+ goto fail;
DT_DISASM_PROG_LINKED(dtp, cflags, dp, stderr, NULL, prp->desc);
if (dp->dtdo_flags & DIFOFLG_DESTRUCTIVE &&
- dest_ok == DTRACEOPT_UNSET)
- return dt_set_errno(dtp, EDT_DESTRUCTIVE);
+ dest_ok == DTRACEOPT_UNSET) {
+ dt_set_errno(dtp, EDT_DESTRUCTIVE);
+ goto fail;
+ }
fd = dt_bpf_load_prog(dtp, prp, dp, cflags);
if (fd == -1)
- return -1;
+ goto fail;
if (prp->prov->impl->attach)
rc = prp->prov->impl->attach(dtp, prp, fd);
if (rc < 0) {
close(fd);
- return dt_attach_error(dtp, rc,
- prp->desc->prv, prp->desc->mod,
- prp->desc->fun, prp->desc->prb);
+ dt_attach_error(dtp, rc,
+ prp->desc->prv, prp->desc->mod,
+ prp->desc->fun, prp->desc->prb);
+ goto fail;
}
}
return 0;
+
+fail:
+ dt_difo_free(dtp, prp->difo);
+ prp->difo = NULL;
+ return -1;
}
diff --git a/libdtrace/dt_prov_uprobe.c b/libdtrace/dt_prov_uprobe.c
index f60bdceb..8e7aa4b0 100644
--- a/libdtrace/dt_prov_uprobe.c
+++ b/libdtrace/dt_prov_uprobe.c
@@ -609,32 +609,40 @@ static int add_probe_uprobe(dtrace_hdl_t *dtp, dt_probe_t *prp)
/* Make program. */
dp = dt_construct(dtp, prp, cflags, NULL);
if (dp == NULL)
- return 0; // FIXME in dt_bpf_make_progs() this is a fatal error; should we do the same here?
+ return 0;
prp->difo = dp;
/* Load program. */
if (dt_link(dtp, prp, dp, NULL) == -1)
- return 0; // FIXME in dt_bpf_load_progs() this is a fatal error; should we do the same here?
+ goto fail;
dtrace_getopt(dtp, "destructive", &dest_ok);
if (dp->dtdo_flags & DIFOFLG_DESTRUCTIVE &&
- dest_ok == DTRACEOPT_UNSET)
- return dt_set_errno(dtp, EDT_DESTRUCTIVE);
+ dest_ok == DTRACEOPT_UNSET) {
+ dt_set_errno(dtp, EDT_DESTRUCTIVE);
+ goto fail;
+ }
fd = dt_bpf_load_prog(dtp, prp, dp, cflags);
if (fd == -1)
- return 0; // FIXME in dt_bpf_load_progs() this is a fatal error; should we do the same here?
+ goto fail;
if (prp->prov->impl->attach)
rc = prp->prov->impl->attach(dtp, prp, fd);
if (rc < 0) {
close(fd);
- return dt_attach_error(dtp, rc, prp->desc->prv, prp->desc->mod,
- prp->desc->fun, prp->desc->prb);
+ dt_attach_error(dtp, rc, prp->desc->prv, prp->desc->mod,
+ prp->desc->fun, prp->desc->prb);
+ goto fail;
}
return 0;
+
+fail:
+ dt_difo_free(dtp, prp->difo);
+ prp->difo = NULL;
+ return 0; // FIXME in dt_bpf_make_progs() this is a fatal error; should we do the same here?
}
static int add_probe_usdt(dtrace_hdl_t *dtp, dt_probe_t *prp)
--
2.45.2
More information about the DTrace-devel
mailing list