On Fri, May 29, 2020 at 10:16 AM piliu <piliu(a)redhat.com> wrote:
On 05/17/2020 10:48 PM, Kairui Song wrote:
> Usually kdump kernel don't need a swiotlb. There are two cases known
> common case a swiotlb is needed:
>
> - SEV/SME is active.
> - crashkernel high reservation is used, or there are crashkernel memory
> above 4G.
>
> For both case, if swiotlb is set to a large value in first kernel, kdump
> kernel will likely to fail with OOM. So don't inherit swiotlb parameter
> by default.
Then is it OK for the two aforementioned cases? Just leave them fixed by
user?
No worry, the swiotlb is not disabled, just not inheriting the size
from first kernel. If swiotlb is required, kernel will enabled it
using default size (64M).
Thanks,
Pingfan
>
> Signed-off-by: Kairui Song <kasong(a)redhat.com>
> ---
> kdump.sysconfig | 2 +-
> kdump.sysconfig.aarch64 | 2 +-
> kdump.sysconfig.i386 | 2 +-
> kdump.sysconfig.ppc64 | 2 +-
> kdump.sysconfig.ppc64le | 2 +-
> kdump.sysconfig.s390x | 2 +-
> kdump.sysconfig.x86_64 | 2 +-
> 7 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/kdump.sysconfig b/kdump.sysconfig
> index df518d6..d8b301c 100644
> --- a/kdump.sysconfig
> +++ b/kdump.sysconfig
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.aarch64 b/kdump.sysconfig.aarch64
> index d5d7624..bcb4a37 100644
> --- a/kdump.sysconfig.aarch64
> +++ b/kdump.sysconfig.aarch64
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.i386 b/kdump.sysconfig.i386
> index c31a8cb..650e405 100644
> --- a/kdump.sysconfig.i386
> +++ b/kdump.sysconfig.i386
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.ppc64 b/kdump.sysconfig.ppc64
> index 1f95452..03fde14 100644
> --- a/kdump.sysconfig.ppc64
> +++ b/kdump.sysconfig.ppc64
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.ppc64le b/kdump.sysconfig.ppc64le
> index 1f95452..03fde14 100644
> --- a/kdump.sysconfig.ppc64le
> +++ b/kdump.sysconfig.ppc64le
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.s390x b/kdump.sysconfig.s390x
> index abd45a2..6effd6d 100644
> --- a/kdump.sysconfig.s390x
> +++ b/kdump.sysconfig.s390x
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
> diff --git a/kdump.sysconfig.x86_64 b/kdump.sysconfig.x86_64
> index a43a970..7b3c68c 100644
> --- a/kdump.sysconfig.x86_64
> +++ b/kdump.sysconfig.x86_64
> @@ -17,7 +17,7 @@ KDUMP_COMMANDLINE=""
> # This variable lets us remove arguments from the current kdump commandline
> # as taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline
> # NOTE: some arguments such as crashkernel will always be removed
> -KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet"
> +KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug quiet swiotlb"
>
> # This variable lets us append arguments to the current kdump commandline
> # after processed by KDUMP_COMMANDLINE_REMOVE
>
--
Best Regards,
Kairui Song