Re: [dpdk-dev] [PATCH] mem: fix cleanup on Windows

[David Marchand <david.marchand@redhat.com>]

On Wed, Mar 24, 2021 at 7:01 PM Dmitry Kozlyuk <dmitry.kozliuk@gmail.com> wrote:
>
> rte_mem_unmap() called from rte_eal_memory_detach() fails on Windows
> with message "EAL: Could not unmap memory: No error". This is because
> on Windows memory is not allocated using mapping. Confusing "No error"
> is caused by using errno instead of rte_errno set by rte_mem_unmap().
>
> Multi-process is not supported on Windows and --in-memory is forced,
> so detaching memory is not needed on cleanup. Bypass the function
> in this case. Fix error handling to produce proper log message.
>
> Fixes: dfbc61a2f9a6 ("mem: detach memsegs on cleanup")
> Cc: Anatoly Burakov <anatoly.burakov@intel.com>
>
> Reported-by: Jie Zhou <jizh@microsoft.com>
> Suggested-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>  lib/librte_eal/common/eal_common_memory.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
> index 0e99986d3d..9ef9c65ac8 100644
> --- a/lib/librte_eal/common/eal_common_memory.c
> +++ b/lib/librte_eal/common/eal_common_memory.c
> @@ -1010,6 +1010,13 @@ rte_eal_memory_detach(void)
>         size_t page_sz = rte_mem_page_size();
>         unsigned int i;
>
> +#ifdef RTE_EXEC_ENV_WINDOWS
> +       /* Multi-process is not supported, detaching is not needed.
> +        * mcfg->mp_status can't be used: it's always "unknown" on Windows.
> +        */
> +       return 0;
> +#endif
> +

My suggestion was more like:
if (eal_get_internal_configuration()->in_memory == 1)
    return 0;


-- 
David Marchand