ACK/Cmnt: [f/j/m/n:linux-aws][PATCH 0/1] aws: Backport latest ENA driver in upstream Linux to enable IRQ moderation

[Tim Gardner]

On 3/7/24 12:32, Philip Cox wrote:
> BugLink: https://bugs.launchpad.net/bugs/2056475
> 
> SRU Justification:
> 
> [Impact]
> In Ubuntu AMIs for x86 and Graviton based EC2 instances, the standard Ubuntu AMI comes without IRQ moderation enabled for ENA, which for our latest generation instances with networking heavy workloads is up to a 25% performance regression (i.e. NGINX in a load-balancing configuration).
> 
> [Fix]
> The mainline Linux kernel will now support IRQ moderation by default for ENA in the 6.9 kernel release via this patch: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/drivers/net/ethernet/amazon/ena?id=50d7a2660579889fba28b7e4543d4ce85aa2311b
> 
> [Test Plan]
> AWS tested
> 
> [Where problems could occur]
> By enabling adaptive coalescing, the default interrupt behaviour will by changed to be more adaptive, which shows improvements on heavy network workloads, but my change the behaviour and performance on other network workloads differently. Rather than handling the interrupts based off of a fixed amount of time elapsed, it will change to an adaptive based approach. There should be no negative impact on light workloads, and a positive impact on heavy work loads. If there is an impact though, this option can be disabled via the ethtool command.
> 
> [Other Info]
> 
> SF: 00380449
> 
> --
> 
> 
> David Arinzon (1):
>    net: ena: Enable DIM by default
> 
>   drivers/net/ethernet/amazon/ena/ena_netdev.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>

50d7a2660579889fba28b7e4543d4ce85aa2311b is upstream
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Tim Gardner
Canonical, Inc