Re: [dpdk-dev] [PATCH v3 10/20] eal/dev: implement device iteration initialization

["Wiles, Keith" <keith.wiles@intel.com>]

> On Mar 27, 2018, at 7:40 AM, Gaëtan Rivet <gaetan.rivet@6wind.com> wrote:
> 
> On Tue, Mar 27, 2018 at 07:47:50AM -0400, Neil Horman wrote:
>> On Tue, Mar 27, 2018 at 01:18:34AM +0200, Gaetan Rivet wrote:
>>> Parse a device description.
>>> Split this description in their relevant part for each layers.
>>> No dynamic allocation is performed.
>>> 
>>> Cc: Neil Horman <nhorman@tuxdriver.com>
>>> Cc: "Wiles, Keith" <keith.wiles@intel.com>
>>> Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
>>> ---
>>> 
>>> This version uses librte_kvargs.
>>> 
>>> lib/Makefile                            |   1 +
>>> lib/librte_eal/bsdapp/eal/Makefile      |   1 +
>>> lib/librte_eal/common/eal_common_dev.c  | 147 ++++++++++++++++++++++++++++++++
>>> lib/librte_eal/common/include/rte_dev.h |  23 +++++
>>> lib/librte_eal/linuxapp/eal/Makefile    |   1 +
>>> lib/librte_eal/rte_eal_version.map      |   1 +
>>> 6 files changed, 174 insertions(+)
>>> 
>>> diff --git a/lib/Makefile b/lib/Makefile
>>> index fc7a55a37..1b17526f7 100644
>>> --- a/lib/Makefile
>>> +++ b/lib/Makefile
>>> @@ -6,6 +6,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
>>> DIRS-y += librte_compat
>>> DIRS-$(CONFIG_RTE_LIBRTE_KVARGS) += librte_kvargs
>>> DIRS-$(CONFIG_RTE_LIBRTE_EAL) += librte_eal
>>> +DEPDIRS-librte_eal := librte_kvargs
>>> DIRS-$(CONFIG_RTE_LIBRTE_PCI) += librte_pci
>>> DEPDIRS-librte_pci := librte_eal
>>> DIRS-$(CONFIG_RTE_LIBRTE_RING) += librte_ring
>>> diff --git a/lib/librte_eal/bsdapp/eal/Makefile b/lib/librte_eal/bsdapp/eal/Makefile
>>> index 17ff1ac45..f6cea7fc2 100644
>>> --- a/lib/librte_eal/bsdapp/eal/Makefile
>>> +++ b/lib/librte_eal/bsdapp/eal/Makefile
>>> @@ -18,6 +18,7 @@ CFLAGS += $(WERROR_FLAGS) -O3
>>> LDLIBS += -lexecinfo
>>> LDLIBS += -lpthread
>>> LDLIBS += -lgcc_s
>>> +LDLIBS += -lrte_kvargs
>>> 
>>> EXPORT_MAP := ../../rte_eal_version.map
>>> 
>>> diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
>>> index cd071442f..1f6df2351 100644
>>> --- a/lib/librte_eal/common/eal_common_dev.c
>>> +++ b/lib/librte_eal/common/eal_common_dev.c
>>> @@ -10,9 +10,12 @@
>>> 
>>> #include <rte_compat.h>
>>> #include <rte_bus.h>
>>> +#include <rte_class.h>
>>> #include <rte_dev.h>
>>> #include <rte_devargs.h>
>>> #include <rte_debug.h>
>>> +#include <rte_errno.h>
>>> +#include <rte_kvargs.h>
>>> #include <rte_log.h>
>>> 
>>> #include "eal_private.h"
>>> @@ -207,3 +210,147 @@ rte_eal_hotplug_remove(const char *busname, const char *devname)
>>> 	rte_eal_devargs_remove(busname, devname);
>>> 	return ret;
>>> }
>>> +
>>> +static size_t
>>> +dev_layer_count(const char *s)
>>> +{
>>> +	size_t i = s ? 1 : 0;
>>> +
>>> +	while (s != NULL && s[0] != '\0') {
>>> +		i += s[0] == '/';
>>> +		s++;
>>> +	}
>>> +	return i;
>>> +}
>>> +
>> So the above code really just counts the number characters in the string,
>> omitting the delimiter character '/', right?  If thats all you want to do, you can just
>> use strtok and strnlen for that, cant you?
> 
> Will do.
> 
>> 
>> Otherwise, this looks pretty good to me
> 
> Please look into the librte_kvargs compatibility patch as well (quite
> short). I'm very unhappy about the logging hack.
> There is always the solution of setting a function pointer on rte_log
> with the proper loglevels and so on.
> Ideally rte_log could be made independent (starting skimming EAL from
> all the fat), but this is much less trivial.

I thought RTE_LOG was setup correctly using defaults, some changes after I looked at must have changed that behavior I guess. That needs to be address at some point IMO, but not in this patch set.

> 
> This implementation relies on librte_kvargs being available. If this is
> not the case, there isn't much point to it.

Looked at the kvargs change and does look correct, but the above needs to be addressed or it will not be logged for normal usage of kvargs. I would have expected RTE_LOG to be able to handle the case of being called before it is inited and just use stderr. It needs to be looked at.

> 
> -- 
> Gaëtan Rivet
> 6WIND

Regards,
Keith