From: Andrea Righi <arighi@nvidia.com>
To: Tejun Heo <tj@kernel.org>
Cc: sched-ext@lists.linux.dev, David Vernet <void@manifault.com>,
Changwoo Min <changwoo@igalia.com>,
Emil Tsalapatis <emil@etsalapatis.com>,
David Dai <david.dai@linux.dev>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] sched_ext: scx_qmap: Read SCX_RESCUE_DISABLE through the enum lookup tables
Date: Fri, 23 Oct 2026 07:45:57 +0200 [thread overview]
Message-ID: <atr0lZ5dHdoZRz68@gpd4> (raw)
In-Reply-To: <20261023000348.2726436-3-tj@kernel.org>
On Thu, Oct 22, 2026 at 02:03:48PM -1000, Tejun Heo wrote:
> 788b494fab1c ("sched_ext: scx_qmap: Drop the compat code") left one compat
> lookup behind: the -B 0 case reads SCX_RESCUE_DISABLE with
> __COMPAT_ENUM_OR_ZERO(). Userspace can read SCX_RESCUE_DISABLE only from BTF
> as it is in the kernel-internal enum scx_consts. The enum lookup tables
> already read their entries from BTF for every scheduler at open time.
>
> Add SCX_RESCUE_DISABLE to the lookup tables and read it from the skeleton's
> rodata. No behavior change.
And, as a reminder, we should add SCX_RESCUE_DISABLE to the scx repo as
well.
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Thanks,
-Andrea
>
> Suggested-by: Andrea Righi <arighi@nvidia.com>
> Link: https://lore.kernel.org/all/ataTuzRFTRm_pax6@gpd4/
> Signed-off-by: Tejun Heo <tj@kernel.org>
> ---
> tools/sched_ext/include/scx/enums.autogen.bpf.h | 3 +++
> tools/sched_ext/include/scx/enums.autogen.h | 1 +
> tools/sched_ext/scx_qmap.c | 2 +-
> 3 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/tools/sched_ext/include/scx/enums.autogen.bpf.h b/tools/sched_ext/include/scx/enums.autogen.bpf.h
> index 405a3e6b8f33..d0c37018659e 100644
> --- a/tools/sched_ext/include/scx/enums.autogen.bpf.h
> +++ b/tools/sched_ext/include/scx/enums.autogen.bpf.h
> @@ -13,6 +13,9 @@ const volatile u64 __SCX_SLICE_DFL __weak;
> const volatile u64 __SCX_SLICE_INF __weak;
> #define SCX_SLICE_INF __SCX_SLICE_INF
>
> +const volatile u64 __SCX_RESCUE_DISABLE __weak;
> +#define SCX_RESCUE_DISABLE __SCX_RESCUE_DISABLE
> +
> const volatile u64 __SCX_RQ_ONLINE __weak;
> #define SCX_RQ_ONLINE __SCX_RQ_ONLINE
>
> diff --git a/tools/sched_ext/include/scx/enums.autogen.h b/tools/sched_ext/include/scx/enums.autogen.h
> index 7ec2e5e41cb2..c4a7260f0983 100644
> --- a/tools/sched_ext/include/scx/enums.autogen.h
> +++ b/tools/sched_ext/include/scx/enums.autogen.h
> @@ -9,6 +9,7 @@
> SCX_ENUM_SET(skel, scx_public_consts, SCX_OPS_NAME_LEN); \
> SCX_ENUM_SET(skel, scx_public_consts, SCX_SLICE_DFL); \
> SCX_ENUM_SET(skel, scx_public_consts, SCX_SLICE_INF); \
> + SCX_ENUM_SET(skel, scx_consts, SCX_RESCUE_DISABLE); \
> SCX_ENUM_SET(skel, scx_rq_flags, SCX_RQ_ONLINE); \
> SCX_ENUM_SET(skel, scx_rq_flags, SCX_RQ_CAN_STOP_TICK); \
> SCX_ENUM_SET(skel, scx_rq_flags, SCX_RQ_BAL_PENDING); \
> diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c
> index 9b1cbe187ebd..fe2f206f5c8a 100644
> --- a/tools/sched_ext/scx_qmap.c
> +++ b/tools/sched_ext/scx_qmap.c
> @@ -427,7 +427,7 @@ int main(int argc, char **argv)
> u32 ppt = strtoul(optarg, NULL, 0);
>
> if (!ppt)
> - ppt = __COMPAT_ENUM_OR_ZERO("scx_consts", "SCX_RESCUE_DISABLE");
> + ppt = skel->rodata->__SCX_RESCUE_DISABLE;
> skel->struct_ops.qmap_ops->rescue_bandwidth_ppt = ppt;
> break;
> }
> --
> 2.56.0
>
>
next prev parent reply other threads:[~2026-10-23 5:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-23 0:03 [PATCHSET sched_ext/for-7.5] sched_ext: Regenerate the enum tables and drop scx_qmap's last compat lookup Tejun Heo
2026-10-23 0:03 ` [PATCH 1/2] sched_ext: Regenerate tools autogen enum headers Tejun Heo
2026-10-23 5:44 ` Andrea Righi
2026-10-23 0:03 ` [PATCH 2/2] sched_ext: scx_qmap: Read SCX_RESCUE_DISABLE through the enum lookup tables Tejun Heo
2026-10-23 5:45 ` Andrea Righi [this message]
2026-10-23 20:26 ` [PATCHSET sched_ext/for-7.5] sched_ext: Regenerate the enum tables and drop scx_qmap's last compat lookup Tejun Heo
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