service: avoid worker lcore exit deadlock
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Commit Message
Calling rte_exit() from a worker lcore thread causes a deadlock in
rte_service_finalize().
This patch makes rte_service_finalize() deadlock-free by avoiding the
need to synchronize with service lcore threads, which in turn is
achieved by moving service and per-lcore state from the heap to being
statically allocated.
The BSS segment increases with ~156 kB (on x86_64 with default
RTE_MAX_LCORE and RTE_SERVICE_NUM_MAX).
According to the service perf autotest, this change also results in a
slight reduction of service framework overhead.
Fixes: 33666b448f15 ("service: fix crash on exit")
Cc: harry.van.haaren@intel.com
Cc: stable@dpdk.org
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
---
lib/eal/common/rte_service.c | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)
Comments
> -----Original Message-----
> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Sent: Tuesday, July 4, 2023 10:44 PM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>; Stephen Hemminger
> <stephen@networkplumber.org>
> Cc: hofors@lysator.liu.se; dev@dpdk.org; Suanming Mou
> <suanmingm@nvidia.com>; thomas@monjalon.net;
> david.marchand@redhat.com; mattias.ronnblom
> <mattias.ronnblom@ericsson.com>; stable@dpdk.org
> Subject: [PATCH] service: avoid worker lcore exit deadlock
>
> Calling rte_exit() from a worker lcore thread causes a deadlock in
> rte_service_finalize().
>
> This patch makes rte_service_finalize() deadlock-free by avoiding the
> need to synchronize with service lcore threads, which in turn is
> achieved by moving service and per-lcore state from the heap to being
> statically allocated.
Elegant solution to avoiding the malloc/free in cleanup issue.
Thanks for investigating & implementing the solution!
> The BSS segment increases with ~156 kB (on x86_64 with default
> RTE_MAX_LCORE and RTE_SERVICE_NUM_MAX).
>
> According to the service perf autotest, this change also results in a
> slight reduction of service framework overhead.
>
> Fixes: 33666b448f15 ("service: fix crash on exit")
> Cc: harry.van.haaren@intel.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>
@@ -15,7 +15,6 @@
#include <rte_common.h>
#include <rte_cycles.h>
#include <rte_atomic.h>
-#include <rte_malloc.h>
#include <rte_spinlock.h>
#include <rte_trace_point.h>
@@ -74,8 +73,8 @@ struct core_state {
} __rte_cache_aligned;
static uint32_t rte_service_count;
-static struct rte_service_spec_impl *rte_services;
-static struct core_state *lcore_states;
+static struct rte_service_spec_impl rte_services[RTE_SERVICE_NUM_MAX];
+static struct core_state lcore_states[RTE_MAX_LCORE];
static uint32_t rte_service_library_initialized;
int32_t
@@ -93,21 +92,6 @@ rte_service_init(void)
return -EALREADY;
}
- rte_services = rte_calloc("rte_services", RTE_SERVICE_NUM_MAX,
- sizeof(struct rte_service_spec_impl),
- RTE_CACHE_LINE_SIZE);
- if (!rte_services) {
- RTE_LOG(ERR, EAL, "error allocating rte services array\n");
- goto fail_mem;
- }
-
- lcore_states = rte_calloc("rte_service_core_states", RTE_MAX_LCORE,
- sizeof(struct core_state), RTE_CACHE_LINE_SIZE);
- if (!lcore_states) {
- RTE_LOG(ERR, EAL, "error allocating core states array\n");
- goto fail_mem;
- }
-
int i;
struct rte_config *cfg = rte_eal_get_configuration();
for (i = 0; i < RTE_MAX_LCORE; i++) {
@@ -120,10 +104,6 @@ rte_service_init(void)
rte_service_library_initialized = 1;
return 0;
-fail_mem:
- rte_free(rte_services);
- rte_free(lcore_states);
- return -ENOMEM;
}
void
@@ -133,10 +113,6 @@ rte_service_finalize(void)
return;
rte_service_lcore_reset_all();
- rte_eal_mp_wait_lcore();
-
- rte_free(rte_services);
- rte_free(lcore_states);
rte_service_library_initialized = 0;
}