Re: [dpdk-dev] [PATCH] Fixed spam from kni_allocate_mbufs() when no mbufs are free.

[Jay Rolette <rolette@infiniteio.com>]

self-NAK now that I know that gmail web client borks up the patches. I'll
re-submit.

Jay

On Fri, Dec 12, 2014 at 7:28 PM, Jay Rolette <rolette@infiniteio.com> wrote:
>
> Fixed spam from kni_allocate_mbufs() when no mbufs are free.
> If mbufs exhausted, 'out of memory' message logged at EXTREMELY high
> rates. Now logs no more than once per 10 mins
>
> Signed-off-by: Jay Rolette <rolette@infiniteio.com>
> ---
>  lib/librte_kni/rte_kni.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
> index fdb7509..f89319c 100644
> --- a/lib/librte_kni/rte_kni.c
> +++ b/lib/librte_kni/rte_kni.c
> @@ -40,6 +40,7 @@
>  #include <unistd.h>
>  #include <sys/ioctl.h>
>
> +#include <rte_cycles.h>
>  #include <rte_spinlock.h>
>  #include <rte_string_fns.h>
>  #include <rte_ethdev.h>
> @@ -61,6 +62,9 @@
>
>  #define KNI_MEM_CHECK(cond) do { if (cond) goto kni_fail; } while (0)
>
> +// Configure how often we log "out of memory" messages (in seconds)
> +#define KNI_SPAM_SUPPRESSION_PERIOD 60*10
> +
>  /**
>   * KNI context
>   */
> @@ -592,6 +596,10 @@ kni_free_mbufs(struct rte_kni *kni)
>  static void
>  kni_allocate_mbufs(struct rte_kni *kni)
>  {
> + static uint64_t no_mbufs = 0;
> + static uint64_t spam_filter = 0;
> + static uint64_t delayPeriod = 0;
> +
>   int i, ret;
>   struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];
>
> @@ -620,7 +628,18 @@ kni_allocate_mbufs(struct rte_kni *kni)
>   pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool);
>   if (unlikely(pkts[i] == NULL)) {
>   /* Out of memory */
> - RTE_LOG(ERR, KNI, "Out of memory\n");
> + no_mbufs++;
> +
> + // Memory leak or need to tune? Regardless, if we get here once,
> + // we will get here a *lot*. Don't spam the logs!
> + now = rte_get_tsc_cycles();
> + if (!delayPeriod)
> +    delayPeriod = rte_get_tsc_hz() * KNI_SPAM_SUPPRESSION_PERIOD;
> +
> + if (!spam_filter || (now - spam_filter) > delayPeriod) {
> + RTE_LOG(ERR, KNI, "No mbufs available (%llu)\n", (unsigned long
> long)no_mbufs);
> + spam_filter = now;
> + }
>   break;
>   }
>   }
> --
>
>