> On Sep 3, 2018, at 4:33 PM, Ilya Maximets <i.maxim...@samsung.com> wrote:
>
> On 03.09.2018 18:14, Wiles, Keith wrote:
>>
>>
>>> On Aug 31, 2018, at 1:45 PM, Ilya Maximets <i.maxim...@samsung.com> wrote:
>>>
>>> NICs uses different delays up to a second during their
>>> configuration. It makes no sense to busy-wait so long wasting
>>> CPU cycles and preventing any other threads to execute on the
>>> same CPU core. These busy polling are the rudiments that came
>>> from the kernel drivers where you can not sleep in interrupt
>>> context, but as we're in userspace, we're able and should
>>> sleep to allow other threads to run.
>>> Delays never called on rx/tx path, so this should not affect
>>> performance.
>>
>> I have a question, the only thread being effected by the busy wait is the
>> thread assigned to the core or the master lcore in the case of
>> rte_eal_init(). It should not effect other threads running on other cores,
>> right? If you do have other threads running in the same code then I see the
>> need, please help me understand the use and how it is effecting DPDK.
>
> Originally, this patch comes from this issue:
> http://mails.dpdk.org/archives/dev/2018-August/110640.html
>
> non-EAL threads is one of the answers.
> For example, main thread in OVS periodically checks the link statuses
> and hangs there busy waiting on different NIC configuration operations.
We have link state get no wait why is that not working instead of wait polling
the line state?
> Also, main OVS tread is responsible for port configuration and
> re-configuration. There are few other in-dpdk threads like interrupts
> handling thread (alarm handling thread). vhost_thread is working on
> the same lcores and wants some time to work too.
>
> In case of hyperthreading busy-waiting will significantly affect
> threads on the siblings.
>
> Best regards, Ilya Maximets.
>
>>>
>>> Signed-off-by: Ilya Maximets <i.maxim...@samsung.com>
>>> ---
>>> drivers/net/avf/Makefile | 1 +
>>> drivers/net/avf/base/avf_osdep.h | 4 ++--
>>> drivers/net/e1000/Makefile | 1 +
>>> drivers/net/e1000/base/e1000_osdep.h | 2 +-
>>> drivers/net/i40e/base/i40e_osdep.h | 6 +++---
>>> drivers/net/ifc/base/ifcvf_osdep.h | 2 +-
>>> drivers/net/ixgbe/base/ixgbe_osdep.h | 2 +-
>>> 7 files changed, 10 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/net/avf/Makefile b/drivers/net/avf/Makefile
>>> index 3f815bbc4..8ee707529 100644
>>> --- a/drivers/net/avf/Makefile
>>> +++ b/drivers/net/avf/Makefile
>>> @@ -9,6 +9,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
>>> LIB = librte_pmd_avf.a
>>>
>>> CFLAGS += -O3
>>> +CFLAGS += -DALLOW_EXPERIMENTAL_API
>>> LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring
>>> LDLIBS += -lrte_ethdev -lrte_net -lrte_kvargs -lrte_hash
>>> LDLIBS += -lrte_bus_pci
>>> diff --git a/drivers/net/avf/base/avf_osdep.h
>>> b/drivers/net/avf/base/avf_osdep.h
>>> index 9ef45968e..442a5acd0 100644
>>> --- a/drivers/net/avf/base/avf_osdep.h
>>> +++ b/drivers/net/avf/base/avf_osdep.h
>>> @@ -93,8 +93,8 @@ typedef uint64_t u64;
>>> #define avf_memset(a, b, c, d) memset((a), (b), (c))
>>> #define avf_memcpy(a, b, c, d) rte_memcpy((a), (b), (c))
>>>
>>> -#define avf_usec_delay(x) rte_delay_us(x)
>>> -#define avf_msec_delay(x) rte_delay_us(1000*(x))
>>> +#define avf_usec_delay(x) rte_delay_us_sleep(x)
>>> +#define avf_msec_delay(x) avf_usec_delay(1000 * (x))
>>>
>>> #define AVF_PCI_REG(reg) rte_read32(reg)
>>> #define AVF_PCI_REG_ADDR(a, reg) \
>>> diff --git a/drivers/net/e1000/Makefile b/drivers/net/e1000/Makefile
>>> index 9c87e883b..0ed627656 100644
>>> --- a/drivers/net/e1000/Makefile
>>> +++ b/drivers/net/e1000/Makefile
>>> @@ -10,6 +10,7 @@ LIB = librte_pmd_e1000.a
>>>
>>> CFLAGS += -O3
>>> CFLAGS += $(WERROR_FLAGS)
>>> +CFLAGS += -DALLOW_EXPERIMENTAL_API
>>> LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring
>>> LDLIBS += -lrte_ethdev -lrte_net -lrte_kvargs
>>> LDLIBS += -lrte_bus_pci
>>> diff --git a/drivers/net/e1000/base/e1000_osdep.h
>>> b/drivers/net/e1000/base/e1000_osdep.h
>>> index b8868049f..5958ea157 100644
>>> --- a/drivers/net/e1000/base/e1000_osdep.h
>>> +++ b/drivers/net/e1000/base/e1000_osdep.h
>>> @@ -48,7 +48,7 @@
>>>
>>> #include "../e1000_logs.h"
>>>
>>> -#define DELAY(x) rte_delay_us(x)
>>> +#define DELAY(x) rte_delay_us_sleep(x)
>>> #define usec_delay(x) DELAY(x)
>>> #define usec_delay_irq(x) DELAY(x)
>>> #define msec_delay(x) DELAY(1000*(x))
>>> diff --git a/drivers/net/i40e/base/i40e_osdep.h
>>> b/drivers/net/i40e/base/i40e_osdep.h
>>> index 8e5c593c9..a6072e153 100644
>>> --- a/drivers/net/i40e/base/i40e_osdep.h
>>> +++ b/drivers/net/i40e/base/i40e_osdep.h
>>> @@ -233,9 +233,9 @@ struct i40e_spinlock {
>>> #define i40e_memcpy(a, b, c, d) rte_memcpy((a), (b), (c))
>>>
>>> #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
>>> -#define DELAY(x) rte_delay_us(x)
>>> -#define i40e_usec_delay(x) rte_delay_us(x)
>>> -#define i40e_msec_delay(x) rte_delay_us(1000*(x))
>>> +#define DELAY(x) rte_delay_us_sleep(x)
>>> +#define i40e_usec_delay(x) DELAY(x)
>>> +#define i40e_msec_delay(x) DELAY(1000 * (x))
>>> #define udelay(x) DELAY(x)
>>> #define msleep(x) DELAY(1000*(x))
>>> #define usleep_range(min, max) msleep(DIV_ROUND_UP(min, 1000))
>>> diff --git a/drivers/net/ifc/base/ifcvf_osdep.h
>>> b/drivers/net/ifc/base/ifcvf_osdep.h
>>> index cf151ef52..6aef25ea4 100644
>>> --- a/drivers/net/ifc/base/ifcvf_osdep.h
>>> +++ b/drivers/net/ifc/base/ifcvf_osdep.h
>>> @@ -17,7 +17,7 @@
>>> #define DEBUGOUT(S, args...) RTE_LOG(DEBUG, PMD, S, ##args)
>>> #define STATIC static
>>>
>>> -#define msec_delay rte_delay_ms
>>> +#define msec_delay(x) rte_delay_us_sleep(1000 * (x))
>>>
>>> #define IFCVF_READ_REG8(reg) rte_read8(reg)
>>> #define IFCVF_WRITE_REG8(val, reg) rte_write8((val), (reg))
>>> diff --git a/drivers/net/ixgbe/base/ixgbe_osdep.h
>>> b/drivers/net/ixgbe/base/ixgbe_osdep.h
>>> index bb5dfd2af..94ede9bc2 100644
>>> --- a/drivers/net/ixgbe/base/ixgbe_osdep.h
>>> +++ b/drivers/net/ixgbe/base/ixgbe_osdep.h
>>> @@ -51,7 +51,7 @@
>>>
>>> #define ASSERT(x) if(!(x)) rte_panic("IXGBE: x")
>>>
>>> -#define DELAY(x) rte_delay_us(x)
>>> +#define DELAY(x) rte_delay_us_sleep(x)
>>> #define usec_delay(x) DELAY(x)
>>> #define msec_delay(x) DELAY(1000*(x))
>>>
>>> --
>>> 2.17.1
>>>
>>
>> Regards,
>> Keith
Regards,
Keith
