[dpdk-dev] [PATCH v4 01/17] eal: add cpuset into per EAL thread lcore_config

[Liang, Cunming]

> -----Original Message-----
> From: Olivier MATZ [mailto:olivier.matz at 6wind.com]
> Sent: Monday, February 09, 2015 4:00 AM
> To: Liang, Cunming; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v4 01/17] eal: add cpuset into per EAL thread
> lcore_config
> 
> Hi,
> 
> On 02/02/2015 03:02 AM, Cunming Liang wrote:
> > The patch adds 'cpuset' into per-lcore configure 'lcore_config[]',
> > as the lcore no longer always 1:1 pinning with physical cpu.
> > The lcore now stands for a EAL thread rather than a logical cpu.
> >
> > It doesn't change the default behavior of 1:1 mapping, but allows to
> > affinity the EAL thread to multiple cpus.
> >
> > [...]
> > diff --git a/lib/librte_eal/bsdapp/eal/eal_memory.c
> b/lib/librte_eal/bsdapp/eal/eal_memory.c
> > index 65ee87d..a34d500 100644
> > --- a/lib/librte_eal/bsdapp/eal/eal_memory.c
> > +++ b/lib/librte_eal/bsdapp/eal/eal_memory.c
> > @@ -45,6 +45,8 @@
> >  #include "eal_internal_cfg.h"
> >  #include "eal_filesystem.h"
> >
> > +/* avoid re-defined against with freebsd header */
> > +#undef PAGE_SIZE
> >  #define PAGE_SIZE (sysconf(_SC_PAGESIZE))
> 
> I don't see the link with the patch. Should this go somewhere else?
> 
> 
> >
> >  /*
> > diff --git a/lib/librte_eal/common/include/rte_lcore.h
> b/lib/librte_eal/common/include/rte_lcore.h
> > index 49b2c03..4c7d6bb 100644
> > --- a/lib/librte_eal/common/include/rte_lcore.h
> > +++ b/lib/librte_eal/common/include/rte_lcore.h
> > @@ -50,6 +50,13 @@ extern "C" {
> >
> >  #define LCORE_ID_ANY -1    /**< Any lcore. */
> >
> > +#if defined(__linux__)
> > +	typedef	cpu_set_t rte_cpuset_t;
> > +#elif defined(__FreeBSD__)
> > +#include <pthread_np.h>
> > +	typedef cpuset_t rte_cpuset_t;
> > +#endif
> > +
> 
> Should we also define RTE_CPU_SETSIZE?
> For linux, should <sched.h> be included?
[LCM] It uses the fix size cpuset, won't use CPU_ALLOC() to get the pointer of cpuset.
The RTE_CPU_SETSIZE always equal to sizeof(rte_cpuset_t).
> 
> If I understand well, after the patch series, the user of
> rte_thread_set_affinity() and rte_thread_get_affinity() are
> supposed to use the macros from sched.h to access to this
> cpuset parameter. So I'm wondering if it's not better to
> use cpu_set_t from libc instead of redefining rte_cpuset_t.
> 
> To reword my question: what is the purpose of redefining
> cpu_set_t in rte_cpuset_t if we still need to use all the
> libc API to access to it?
[LCM] In linux the type is *cpu_set_t*, but in freebsd it's *cpuset_t*.
The purpose of *rte_cpuset_t* is to make the consistent type definition in EAL, and to avoid lots of #ifdef for this diff.
In either linux or freebsd, it still can use the MACRO in libc to set the rte_cpuset_t.
> 
> 
> Regards,
> Olivier