[dpdk-dev] [PATCH v3] timer: fix resource leak in finalize

[Burakov, Anatoly]

On 08-May-19 11:35 PM, Erik Gabriel Carrillo wrote:
> By using a lock added to the rte_mem_config (which lives in shared
> memory), we can synchronize multiple processes in init/finalize and
> safely free allocations made during init.
> 
> Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo at intel.com>
> ---
> changes in v3:
>   - The previous version had race condition.  This version fixes the race
>     by adding a lock in shared memory outside of the DPDK heap area
>     that can be used to safely free the memzone reserved in the subsystem
>     init call. (Anatoly)
> 
>     This patch depends on http://patches.dpdk.org/patch/53333/.
>   
> changes in v2:
>   - Handle scenario where primary process exits before secondaries such
>     that memzone is not freed early (Anatoly)
> 
>   lib/librte_eal/common/include/rte_eal_memconfig.h |  3 +++
>   lib/librte_timer/rte_timer.c                      | 23 ++++++++++++++++++++++-
>   2 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_eal/common/include/rte_eal_memconfig.h b/lib/librte_eal/common/include/rte_eal_memconfig.h
> index 84aabe3..8cbc09c 100644
> --- a/lib/librte_eal/common/include/rte_eal_memconfig.h
> +++ b/lib/librte_eal/common/include/rte_eal_memconfig.h
> @@ -64,6 +64,9 @@ struct rte_mem_config {
>   	rte_rwlock_t memory_hotplug_lock;
>   	/**< indicates whether memory hotplug request is in progress. */
>   
> +	rte_spinlock_t timer_subsystem_lock;
> +	/**< indicates whether timer subsystem init/finalize is in progress. */
> +

I believe there's an initialize function somewhere which will initialize 
all of these locks. This lock should be in there as well.

Other than that, i'm OK with this change, however i feel like /just/ 
adding this would be a missed opportunity, because next time we want to 
add something here it will be an ABI break again.

We could perhaps use this opportunity to leave some padding for future 
data. I'm not sure how would that look like, just an idea floating in my 
head :)

-- 
Thanks,
Anatoly