Author: np
Date: Wed Jul 23 22:29:22 2014
New Revision: 269032
URL: http://svnweb.freebsd.org/changeset/base/269032
Log:
cxgbe(4): Keep track of the clusters that have to be freed by the
custom free routine (rxb_free) in the driver. Fail MOD_UNLOAD with
EBUSY if any such cluster has been handed up to the kernel but hasn't
been freed yet. This prevents a panic later when the cluster finally
needs to be freed but rxb_free is gone from the kernel.
MFC after: 1 week
Modified:
head/sys/dev/cxgbe/adapter.h
head/sys/dev/cxgbe/t4_main.c
head/sys/dev/cxgbe/t4_sge.c
Modified: head/sys/dev/cxgbe/adapter.h
==============================================================================
--- head/sys/dev/cxgbe/adapter.h Wed Jul 23 22:18:43 2014
(r269031)
+++ head/sys/dev/cxgbe/adapter.h Wed Jul 23 22:29:22 2014
(r269032)
@@ -985,6 +985,8 @@ void t4_nm_intr(void *);
/* t4_sge.c */
void t4_sge_modload(void);
+void t4_sge_modunload(void);
+uint64_t t4_sge_extfree_refs(void);
void t4_init_sge_cpl_handlers(struct adapter *);
void t4_tweak_chip_settings(struct adapter *);
int t4_read_chip_settings(struct adapter *);
Modified: head/sys/dev/cxgbe/t4_main.c
==============================================================================
--- head/sys/dev/cxgbe/t4_main.c Wed Jul 23 22:18:43 2014
(r269031)
+++ head/sys/dev/cxgbe/t4_main.c Wed Jul 23 22:29:22 2014
(r269032)
@@ -8259,6 +8259,9 @@ tweak_tunables(void)
t4_intr_types &= INTR_MSIX | INTR_MSI | INTR_INTX;
}
+static struct sx mlu; /* mod load unload */
+SX_SYSINIT(cxgbe_mlu, &mlu, "cxgbe mod load/unload");
+
static int
mod_event(module_t mod, int cmd, void *arg)
{
@@ -8267,41 +8270,67 @@ mod_event(module_t mod, int cmd, void *a
switch (cmd) {
case MOD_LOAD:
- if (atomic_fetchadd_int(&loaded, 1))
- break;
- t4_sge_modload();
- sx_init(&t4_list_lock, "T4/T5 adapters");
- SLIST_INIT(&t4_list);
+ sx_xlock(&mlu);
+ if (loaded++ == 0) {
+ t4_sge_modload();
+ sx_init(&t4_list_lock, "T4/T5 adapters");
+ SLIST_INIT(&t4_list);
#ifdef TCP_OFFLOAD
- sx_init(&t4_uld_list_lock, "T4/T5 ULDs");
- SLIST_INIT(&t4_uld_list);
+ sx_init(&t4_uld_list_lock, "T4/T5 ULDs");
+ SLIST_INIT(&t4_uld_list);
#endif
- t4_tracer_modload();
- tweak_tunables();
+ t4_tracer_modload();
+ tweak_tunables();
+ }
+ sx_xunlock(&mlu);
break;
case MOD_UNLOAD:
- if (atomic_fetchadd_int(&loaded, -1) > 1)
- break;
- t4_tracer_modunload();
+ sx_xlock(&mlu);
+ if (--loaded == 0) {
+ int tries;
+
+ sx_slock(&t4_list_lock);
+ if (!SLIST_EMPTY(&t4_list)) {
+ rc = EBUSY;
+ sx_sunlock(&t4_list_lock);
+ goto done_unload;
+ }
+#ifdef TCP_OFFLOAD
+ sx_slock(&t4_uld_list_lock);
+ if (!SLIST_EMPTY(&t4_uld_list)) {
+ rc = EBUSY;
+ sx_sunlock(&t4_uld_list_lock);
+ sx_sunlock(&t4_list_lock);
+ goto done_unload;
+ }
+#endif
+ tries = 0;
+ while (tries++ < 5 && t4_sge_extfree_refs() != 0) {
+ uprintf("%ju clusters with custom free routine "
+ "still is use.\n", t4_sge_extfree_refs());
+ pause("t4unload", 2 * hz);
+ }
#ifdef TCP_OFFLOAD
- sx_slock(&t4_uld_list_lock);
- if (!SLIST_EMPTY(&t4_uld_list)) {
- rc = EBUSY;
sx_sunlock(&t4_uld_list_lock);
- break;
- }
- sx_sunlock(&t4_uld_list_lock);
- sx_destroy(&t4_uld_list_lock);
#endif
- sx_slock(&t4_list_lock);
- if (!SLIST_EMPTY(&t4_list)) {
- rc = EBUSY;
sx_sunlock(&t4_list_lock);
- break;
+
+ if (t4_sge_extfree_refs() == 0) {
+ t4_tracer_modunload();
+#ifdef TCP_OFFLOAD
+ sx_destroy(&t4_uld_list_lock);
+#endif
+ sx_destroy(&t4_list_lock);
+ t4_sge_modunload();
+ loaded = 0;
+ } else {
+ rc = EBUSY;
+ loaded++; /* undo earlier decrement */
+ }
}
- sx_sunlock(&t4_list_lock);
- sx_destroy(&t4_list_lock);
+done_unload:
+ sx_xunlock(&mlu);
break;
}
Modified: head/sys/dev/cxgbe/t4_sge.c
==============================================================================
--- head/sys/dev/cxgbe/t4_sge.c Wed Jul 23 22:18:43 2014 (r269031)
+++ head/sys/dev/cxgbe/t4_sge.c Wed Jul 23 22:29:22 2014 (r269032)
@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/smp.h>
+#include <sys/counter.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
@@ -258,6 +259,9 @@ static int handle_fw_msg(struct sge_iq *
static int sysctl_uint16(SYSCTL_HANDLER_ARGS);
static int sysctl_bufsizes(SYSCTL_HANDLER_ARGS);
+static counter_u64_t extfree_refs;
+static counter_u64_t extfree_rels;
+
/*
* Called on MOD_LOAD. Validates and calculates the SGE tunables.
*/
@@ -329,6 +333,30 @@ t4_sge_modload(void)
" using 0 instead.\n", cong_drop);
cong_drop = 0;
}
+
+ extfree_refs = counter_u64_alloc(M_WAITOK);
+ extfree_rels = counter_u64_alloc(M_WAITOK);
+ counter_u64_zero(extfree_refs);
+ counter_u64_zero(extfree_rels);
+}
+
+void
+t4_sge_modunload(void)
+{
+
+ counter_u64_free(extfree_refs);
+ counter_u64_free(extfree_rels);
+}
+
+uint64_t
+t4_sge_extfree_refs(void)
+{
+ uint64_t refs, rels;
+
+ rels = counter_u64_fetch(extfree_rels);
+ refs = counter_u64_fetch(extfree_refs);
+
+ return (refs - rels);
}
void
@@ -1513,6 +1541,7 @@ rxb_free(struct mbuf *m, void *arg1, voi
caddr_t cl = arg2;
uma_zfree(zone, cl);
+ counter_u64_add(extfree_rels, 1);
}
/*
@@ -1574,7 +1603,8 @@ get_scatter_segment(struct adapter *sc,
fl->mbuf_inlined++;
m_extaddref(m, payload, padded_len, &clm->refcount, rxb_free,
swz->zone, sd->cl);
- sd->nmbuf++;
+ if (sd->nmbuf++ == 0)
+ counter_u64_add(extfree_refs, 1);
} else {
@@ -1591,7 +1621,8 @@ get_scatter_segment(struct adapter *sc,
if (clm != NULL) {
m_extaddref(m, payload, padded_len, &clm->refcount,
rxb_free, swz->zone, sd->cl);
- sd->nmbuf++;
+ if (sd->nmbuf++ == 0)
+ counter_u64_add(extfree_refs, 1);
} else {
m_cljset(m, sd->cl, swz->type);
sd->cl = NULL; /* consumed, not a recycle candidate */
@@ -3280,6 +3311,7 @@ refill_fl(struct adapter *sc, struct sge
if (atomic_fetchadd_int(&clm->refcount, -1) == 1) {
fl->cl_recycled++;
+ counter_u64_add(extfree_rels, 1);
goto recycled;
}
sd->cl = NULL; /* gave up my reference */
@@ -3381,9 +3413,11 @@ free_fl_sdesc(struct adapter *sc, struct
cll = &sd->cll;
clm = cl_metadata(sc, fl, cll, sd->cl);
- if (sd->nmbuf == 0 ||
- (clm && atomic_fetchadd_int(&clm->refcount, -1) == 1)) {
+ if (sd->nmbuf == 0)
+ uma_zfree(sc->sge.sw_zone_info[cll->zidx].zone, sd->cl);
+ else if (clm && atomic_fetchadd_int(&clm->refcount, -1) == 1) {
uma_zfree(sc->sge.sw_zone_info[cll->zidx].zone, sd->cl);
+ counter_u64_add(extfree_rels, 1);
}
sd->cl = NULL;
}
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