From: Jakub Kicinski <kuba@kernel.org>
To: Jacob Keller <jacob.e.keller@intel.com>
Cc: Rahul Rameshbabu <rrameshbabu@nvidia.com>,
Saeed Mahameed <saeed@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>,
Eric Dumazet <edumazet@google.com>,
Saeed Mahameed <saeedm@nvidia.com>, <netdev@vger.kernel.org>,
Tariq Toukan <tariqt@nvidia.com>, Gal Pressman <gal@nvidia.com>,
Richard Cochran <richardcochran@gmail.com>,
Vincent Cheng <vincent.cheng.xh@renesas.com>
Subject: Re: [net-next 03/15] net/mlx5: Add adjphase function to support hardware-only offset control
Date: Fri, 20 Jan 2023 16:06:09 -0800 [thread overview]
Message-ID: <20230120160609.19160723@kernel.org> (raw)
In-Reply-To: <3312dd93-398d-f891-1170-5d471b3d7482@intel.com>
On Fri, 20 Jan 2023 15:58:25 -0800 Jacob Keller wrote:
> Sure. I guess what I don't understand is why or when one would want to
> use adjphase instead of just performing frequency adjustment via the
> .adjfine operation...
>
> Especially since "gradual adjustment over time" means it will still be
> slow to converge (just like adjusting frequency is today).
>
> We should definitely improve the doc to explain the diff between them
> and make sure that its more clear to driver implementations.
Fair point, I assumed that the adjustment is precise (as in the device
is programmed with both the extra addend and number of cycles over
which to use it). Yielding an exact adjustment.
But then again, I also thought that .adjtime is supposed to be a precise
single-shot nudge, while most drivers just do:
time = read_time()
time += delta
write_time(time)
:S So yeah, let's document..
> It also makes it harder to justify mapping small .adjtime to .adjphase,
> as it seems like .adjphase isn't required to adjust the offset
> immediately. Perhaps the adjustment size is small enough that isn't a
> big problem?
next prev parent reply other threads:[~2023-01-21 0:06 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-18 18:35 [pull request][net-next 00/15] mlx5 updates 2023-01-18 Saeed Mahameed
2023-01-18 18:35 ` [net-next 01/15] net/mlx5e: Suppress Send WQEBB room warning for PAGE_SIZE >= 16KB Saeed Mahameed
2023-01-18 21:31 ` Jacob Keller
2023-01-20 4:00 ` patchwork-bot+netdevbpf
2023-01-18 18:35 ` [net-next 02/15] net/mlx5: Suppress error logging on UCTX creation Saeed Mahameed
2023-01-18 21:32 ` Jacob Keller
2023-01-18 18:35 ` [net-next 03/15] net/mlx5: Add adjphase function to support hardware-only offset control Saeed Mahameed
2023-01-18 21:33 ` Jacob Keller
2023-01-20 3:46 ` Jakub Kicinski
2023-01-20 3:56 ` Rahul Rameshbabu
2023-01-20 4:03 ` Jakub Kicinski
2023-01-20 4:26 ` Rahul Rameshbabu
2023-01-20 5:08 ` Jakub Kicinski
2023-01-20 5:22 ` Rahul Rameshbabu
2023-01-20 5:45 ` Jakub Kicinski
2023-01-20 6:02 ` Rahul Rameshbabu
2023-01-20 17:21 ` Jacob Keller
2023-01-20 18:00 ` Rahul Rameshbabu
2023-01-20 23:58 ` Jacob Keller
2023-01-21 0:06 ` Jakub Kicinski [this message]
2023-01-22 21:11 ` Rahul Rameshbabu
2023-01-23 2:22 ` Richard Cochran
2023-01-23 2:48 ` Rahul Rameshbabu
2023-01-23 2:58 ` Richard Cochran
2023-01-23 18:44 ` Rahul Rameshbabu
2023-01-23 19:13 ` Jacob Keller
2023-01-23 22:39 ` Richard Cochran
2023-01-23 22:36 ` Richard Cochran
2023-01-24 10:33 ` Bar Shapira
2023-01-24 19:15 ` Richard Cochran
2023-01-25 0:48 ` Jakub Kicinski
2023-01-25 2:26 ` Rahul Rameshbabu
2023-01-25 8:28 ` Gal Pressman
2023-01-23 2:15 ` Richard Cochran
2023-01-23 18:14 ` Jacob Keller
2023-01-18 18:35 ` [net-next 04/15] net/mlx5: Add hardware extended range support for PTP adjtime and adjphase Saeed Mahameed
2023-01-18 21:35 ` Jacob Keller
2023-01-18 18:35 ` [net-next 05/15] net/mlx5: E-switch, Remove redundant comment about meta rules Saeed Mahameed
2023-01-18 21:40 ` Jacob Keller
2023-01-18 18:35 ` [net-next 06/15] net/mlx5e: Fail with messages when params are not valid for XSK Saeed Mahameed
2023-01-18 21:41 ` Jacob Keller
2023-01-18 18:35 ` [net-next 07/15] net/mlx5e: Add warning when log WQE size is smaller than log stride size Saeed Mahameed
2023-01-18 21:42 ` Jacob Keller
2023-01-18 18:35 ` [net-next 08/15] net/mlx5e: TC, Pass flow attr to attach/detach mod hdr functions Saeed Mahameed
2023-01-18 21:42 ` Jacob Keller
2023-01-18 18:35 ` [net-next 09/15] net/mlx5e: TC, Add tc prefix to attach/detach " Saeed Mahameed
2023-01-18 21:44 ` Jacob Keller
2023-01-18 18:35 ` [net-next 10/15] net/mlx5e: TC, Use common function allocating flow mod hdr or encap mod hdr Saeed Mahameed
2023-01-18 21:45 ` Jacob Keller
2023-01-18 18:35 ` [net-next 11/15] net/mlx5e: Warn when destroying mod hdr hash table that is not empty Saeed Mahameed
2023-01-18 21:45 ` Jacob Keller
2023-01-18 18:35 ` [net-next 12/15] net/mlx5: E-Switch, Fix typo for egress Saeed Mahameed
2023-01-18 21:46 ` Jacob Keller
2023-01-18 18:36 ` [net-next 13/15] net/mlx5e: Support Geneve and GRE with VF tunnel offload Saeed Mahameed
2023-01-18 21:48 ` Jacob Keller
2023-01-18 18:36 ` [net-next 14/15] net/mlx5e: Remove redundant allocation of spec in create indirect fwd group Saeed Mahameed
2023-01-18 21:50 ` Jacob Keller
2023-01-18 18:36 ` [net-next 15/15] net/mlx5e: Use read lock for eswitch get callbacks Saeed Mahameed
2023-01-18 21:51 ` Jacob Keller
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