Hi Jan,
On 05/29/2015 12:34 PM, Jan Blunck wrote:
> In rte_log_dump_history() the log_history list is reinitialized without
> resetting the log_history_size. In the next call to rte_log_add_in_history()
> the log_history_size > RTE_LOG_HISTORY and the code unconditionally tries
> to remove the first entry:
>
> Program received signal SIGSEGV, Segmentation fault.
> rte_log_add_in_history (
> buf=buf at entry=0x7f02035cd000 "DATAPLANE: 9:dp0s7 link RTM_NEWLINK
> [dp0s7] <UP,BROADCAST,RUNNING,MULTICAST,LOWER_UP>\nCAST,LOWER_UP>\n",
> size=size at entry=86)
> at /usr/src/packages/BUILD/lib/librte_eal/common/eal_common_log.c:122
>
> Signed-off-by: Jan Blunck <jblunck at infradead.org>
> ---
> lib/librte_eal/common/eal_common_log.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/common/eal_common_log.c
> b/lib/librte_eal/common/eal_common_log.c
> index fe3d7d5..cb4311c 100644
> --- a/lib/librte_eal/common/eal_common_log.c
> +++ b/lib/librte_eal/common/eal_common_log.c
> @@ -119,7 +119,8 @@ rte_log_add_in_history(const char *buf, size_t size)
> /* get a buffer for adding in history */
> if (log_history_size > RTE_LOG_HISTORY) {
> hist_buf = STAILQ_FIRST(&log_history);
> - STAILQ_REMOVE_HEAD(&log_history, next);
> + if (hist_buf)
> + STAILQ_REMOVE_HEAD(&log_history, next);
Shouldn't we decrease log_history_size here?
Also, it's probably a bit off-topic, but I think the function that
adds in history could be optimized a bit to avoid doing the copy with
the lock held. Maybe something like this is feasible:
rte_mempool_mc_get() into hist_buf
memcpy(hist_buf->buf, buf, size);
rte_spinlock_lock(&log_list_lock
if (log_history_size > RTE_LOG_HISTORY) {
STAILQ_REMOVE_HEAD
log_history_size --
}
STAILQ_INSERT_TAIL
log_history_size ++
rte_spinlock_unlock(&log_list_lock)
Feel free to implement it if you feel it's better. It would also
require to increase the number of objects in the pool to
RTE_LOG_HISTORY*2 + RTE_MAX_LCORE
Regards,
Olivier
> }
> else {
> if (rte_mempool_mc_get(log_history_mp, &obj) < 0)
> @@ -234,6 +235,7 @@ rte_log_dump_history(FILE *out)
> rte_spinlock_lock(&log_list_lock);
> tmp_log_history = log_history;
> STAILQ_INIT(&log_history);
> + log_history_size = 0;
> rte_spinlock_unlock(&log_list_lock);
>
> for (i=0; i<RTE_LOG_HISTORY; i++) {
>
