Re: [PATCH 2/2] net/mlx5: improve log file path

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 4 Mar 2025 06:23:06 +0000
Bing Zhao <bingz@nvidia.com> wrote:

> Hi Ming,
> 
> > -----Original Message-----
> > From: Yang Ming <ming.1.yang@nokia-sbell.com>
> > Sent: Friday, December 13, 2024 5:25 PM
> > To: Dariusz Sosnowski <dsosnowski@nvidia.com>; Slava Ovsiienko
> > <viacheslavo@nvidia.com>; Bing Zhao <bingz@nvidia.com>; Ori Kam
> > <orika@nvidia.com>; Suanming Mou <suanmingm@nvidia.com>; Matan Azrad
> > <matan@nvidia.com>
> > Cc: dev@dpdk.org; Yang Ming <ming.1.yang@nokia-sbell.com>
> > Subject: [PATCH 2/2] net/mlx5: improve log file path
> > 
> > External email: Use caution opening links or attachments
> > 
> > 
> > 1. /var/log is hard code which is not a good coding style.
> > 2. /var/log may be not allowed to be written via container's read-only
> > mode.
> > 
> > Signed-off-by: Yang Ming <ming.1.yang@nokia-sbell.com>
> > ---
> >  drivers/net/mlx5/mlx5_rxtx.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> > index eadadcdffb..a0da73c9c3 100644
> > --- a/drivers/net/mlx5/mlx5_rxtx.c
> > +++ b/drivers/net/mlx5/mlx5_rxtx.c
> > @@ -12,6 +12,7 @@
> >  #include <rte_prefetch.h>
> >  #include <rte_common.h>
> >  #include <rte_branch_prediction.h>
> > +#include <rte_eal.h>
> >  #include <rte_ether.h>
> >  #include <rte_cycles.h>
> >  #include <rte_flow.h>
> > @@ -311,7 +312,7 @@ mlx5_set_swp_types_table(void)
> >         }
> >  }
> > 
> > -#define MLX5_SYSTEM_LOG_DIR "/var/log"
> > +#define MLX5_SYSTEM_LOG_DIR rte_eal_get_runtime_dir()  
> 
> I agree that using the fixed PATH is not a good practice. Can you ensure that the runtime DIR is with RW+ permissions?

Drivers doing any kind of custom logging is bad practice.
This should be handled by EAL logging, not private fprintf's