On 3/23/2021 10:13 AM, Ferruh Yigit wrote:
On 3/22/2021 6:53 PM, Ananyev, Konstantin wrote:
-----Original Message-----
From: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
Sent: Monday, March 22, 2021 5:08 PM
To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Yigit, Ferruh
<ferruh.yi...@intel.com>; Lijun Ou <ouli...@huawei.com>;
tho...@monjalon.net
Cc: dev@dpdk.org; linux...@openeuler.org; Andrew Rybchenko
<arybche...@solarflare.com>; David Marchand
<david.march...@redhat.com>; Ray Kinsella <m...@ashroe.eu>; Luca Boccassi
<bl...@debian.org>
Subject: Re: [dpdk-dev] [PATCH] ethdev: add queue state when retrieve queue
information
On 3/22/21 7:53 PM, Ananyev, Konstantin wrote:
-----Original Message-----
From: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
Sent: Monday, March 22, 2021 4:02 PM
To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Yigit, Ferruh
<ferruh.yi...@intel.com>; Lijun Ou <ouli...@huawei.com>;
tho...@monjalon.net
Cc: dev@dpdk.org; linux...@openeuler.org; Andrew Rybchenko
<arybche...@solarflare.com>; David Marchand
<david.march...@redhat.com>; Ray Kinsella <m...@ashroe.eu>; Luca Boccassi
<bl...@debian.org>
Subject: Re: [dpdk-dev] [PATCH] ethdev: add queue state when retrieve queue
information
On 3/22/21 6:45 PM, Ananyev, Konstantin wrote:
-----Original Message-----
From: dev <dev-boun...@dpdk.org> On Behalf Of Andrew Rybchenko
Sent: Monday, March 22, 2021 2:49 PM
To: Yigit, Ferruh <ferruh.yi...@intel.com>; Lijun Ou
<ouli...@huawei.com>; tho...@monjalon.net
Cc: dev@dpdk.org; linux...@openeuler.org; Andrew Rybchenko
<arybche...@solarflare.com>; David Marchand
<david.march...@redhat.com>; Ray Kinsella <m...@ashroe.eu>; Luca Boccassi
<bl...@debian.org>
Subject: Re: [dpdk-dev] [PATCH] ethdev: add queue state when retrieve
queue information
On 3/22/21 12:22 PM, Ferruh Yigit wrote:
On 3/18/2021 12:25 PM, Lijun Ou wrote:
Currently, upper-layer application could get queue state only
through pointers such as dev->data->tx_queue_state[queue_id],
this is not the recommended way to access it. So this patch
add get queue state when call rte_eth_rx_queue_info_get and
rte_eth_tx_queue_info_get API.
Note: The hairpin queue is not supported with above
rte_eth_*x_queue_info_get, so the queue state could be
RTE_ETH_QUEUE_STATE_STARTED or RTE_ETH_QUEUE_STATE_STOPPED.
Note: After add queue_state field, the 'struct rte_eth_rxq_info' size
remains 128B, and the 'struct rte_eth_txq_info' size remains 64B, so
it could be ABI compatible.
Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
Signed-off-by: Lijun Ou <ouli...@huawei.com>
<...>
diff --git a/lib/librte_ethdev/rte_ethdev.h
b/lib/librte_ethdev/rte_ethdev.h
index efda313..3b83c5a 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -1591,6 +1591,8 @@ struct rte_eth_rxq_info {
uint8_t scattered_rx; /**< scattered packets RX supported. */
uint16_t nb_desc; /**< configured number of RXDs. */
uint16_t rx_buf_size; /**< hardware receive buffer size. */
+ /**< Queues state: STARTED(1) / STOPPED(0). */
+ uint8_t queue_state;
} __rte_cache_min_aligned;
/**
@@ -1600,6 +1602,8 @@ struct rte_eth_rxq_info {
struct rte_eth_txq_info {
struct rte_eth_txconf conf; /**< queue config parameters. */
uint16_t nb_desc; /**< configured number of TXDs. */
+ /**< Queues state: STARTED(1) / STOPPED(0). */
+ uint8_t queue_state;
} __rte_cache_min_aligned;
/* Generic Burst mode flag definition, values can be ORed. */
This is causing an ABI warning [1], but I guess it is safe since the
size of the struct is not changing (cache align). Adding a few more
people to comment.
[1]
https://travis-ci.com/github/ovsrobot/dpdk/builds/220497651
Frankly speaking I dislike addition of queue_state as uint8_t.
IMHO it should be either 'bool started' or enum to support more
states in the future if we need.
I think we already have set of defines for it:
lib/librte_ethdev/rte_ethdev_driver.h:925:#define
RTE_ETH_QUEUE_STATE_STOPPED 0
lib/librte_ethdev/rte_ethdev_driver.h:926:#define
RTE_ETH_QUEUE_STATE_STARTED 1
lib/librte_ethdev/rte_ethdev_driver.h:927:#define
RTE_ETH_QUEUE_STATE_HAIRPIN 2
If we want to publish it, then might be enough just move these macros to
rte_ethdev.h or so.
About uint8_t vs enum - yes, in principle enum would be a bit nicer,
but right now rte_eth_dev_data.(rx|tx)_queue_state[] itself is an array
of uint8_t.
So probably not much point to waste extra 3B in rte_eth_(rxq|txq)_info.
Unless in future will want to change it in struct rte_eth_dev_data too
(or even hide it inside dev private queue data).
I forgot about hairpin and bitmask... If so, I think it is
sufficient to fix absolutely misleading comment, say
that it is a bit mask and think about removal of
RTE_ETH_QUEUE_STATE_STOPPED (since it could be
stopped+hairpin). May be consider to use uin16_t,
since 8 bit is really small bitmask. It still fits in
available hole.
Hmm, as I can read the code - hairpin queue can't be started/stopped by SW,
and each of the states (stopped/started/hairpin) is mutually exclusive.
Is that not what was intended when hairpin queues were introduced?
Thanks, yes, you're right. My memory lies to me. If queue state
is not a bit mask, it should be an enum from API point of view.
Rx/Tx queue info structures are control path. I see no point to
save bits here. Clear API is more important on control path.
The only reason here to use uint8_t is to avoid ABI breakage.
I can't judge if it is critical to wait or not.
As alternate thought - introduce new API function,
something like:
int rte_eth_get_rxq_state(portid, queue_id);
Then rte_eth_dev_is_rx_hairpin_queue() probably can be deprecated
in favour of this new one.
The 'rte_eth_dev_is_rx_hairpin_queue()' is internal function, and it is not
visible to the application, it should be OK to keep it.
But 'STATE_HAIRPIN' should be kept internal, or should be available to the
application?
The actual need is to know the start/stop state of the queue. That is for app to
decide if 'rte_eth_tx_done_cleanup()' can be done or not an a queue:
https://patches.dpdk.org/project/dpdk/patch/1614938252-62955-1-git-send-email-ouli...@huawei.com/
And normally I also prefer APIs with simple & clear responsibility, but this one
seems very related to the existing '_queue_info_get()' ones, so I am fine with
both options.
Another high-level discussion is, testpmd keeps lots of config/state itself, I
assume that is because it is not possible to get all DPDK config/state from DPDK
library, but not sure if this is a design decision.
Should we try to provide all config/state information via DPDK APIs, or should
we push this responsibility to the application level?
