ACK: [SRU][F:aws][PATCH v2 0/1] Set CONFIG_LOG_BUF_SHIFT=18 on all 64bit arches

[Jian Hui Lee]

Acked-by: Jian Hui Lee <jianhui.lee at canonical.com>

On Thu, Nov 7, 2024 at 3:23 PM Koichiro Den <koichiro.den at canonical.com> wrote:
>
> BugLink: https://bugs.launchpad.net/bugs/2085493
>
> SRU Justification:
>
> [Impact]
>
> CONFIG_LOG_BUF_SHIFT has been kept at 14 on arm64 instances. The small
> log_buf has led to sporadic test failures (see LP#2085493). Furthermore,
> since it can easily fill up before systemd-journald starts, some boot
> kernel log messages may be lost. Align the settings with master kernel
> for simplicity's sake, including other architectures.
>
> [Fix]
>
> Set CONFIG_LOG_BUF_SHIFT=18, which is sufficient in normal
> circumstances.
>
> [Test Plan]
>
> Boot testing suffices.
> I have tested with log_buf_len=256K on b:linux-aws-5.4 and confirmed that the
> sporadic failures observed in LP#2085493 disappeared.
>
> [Where problems could occur]
>
> Raising the size of the log_buf will increase kernel memory usage
> which cannot be reclaimed. On arm64 instance types, the size will
> increase from 16 KB to 256 KB. Users who want to keep it at 16 KB
> might need to explicitly set log_buf_len= kernel parameter.
>
> [Notes]
>
> v2:
>   - fix BugLink in commit message + fix subject
>
>
> Koichiro Den (1):
>   UBUNTU: [Config] aws: CONFIG_LOG_BUF_SHIFT=18 on all 64bit arches
>
>  debian.aws/config/annotations | 1 -
>  1 file changed, 1 deletion(-)
>
> --
> 2.43.0
>
>
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