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| author | Tejun Heo <tj@kernel.org> | 2026-09-14 22:12:34 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-09-15 06:57:20 -1000 |
| commit | a9e3760b0838299649c0d57cca44daaf40ba3c33 (patch) | |
| tree | 95807ff0e511c05602ef34808cfc660303309057 /samples/bpf/net_shared.h | |
| download | linux-stable-a9e3760b0838299649c0d57cca44daaf40ba3c33.tar.gz linux-stable-a9e3760b0838299649c0d57cca44daaf40ba3c33.zip | |
sched_ext: Maintain an online cid mask in the scheduler arenagrafted
Schedulers on the default cid mapping treat [0, nr_online_cids) as the
online set and restart on hotplug. Schedulers that install their own mapping
with scx_bpf_cid_override() have no way to learn which cids are online: the
count no longer identifies members and the CPU-form cpumask is unusable from
cid programs. This is an obvious hole in the cid API.
Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's
arena, allocated alongside the per-CPU scratch masks and populated after the
cid mapping is finalized and before ops.init(), for child schedulers too.
The pointer stays valid through ops.exit() with no reference to take. It is
the arena offset as a void pointer, the same form struct_ops arena arguments
arrive in. The verifier types the void return as a scalar for the program's
arena cast.
The mask follows the SCX hotplug notifications: seeded from cpu_active_mask
and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask
only inside a hotplug transition. Updates walk the scheduler list under the
lock that also serializes unlinking. Reads are live, not atomic snapshots.
Root initialization excludes hotplug.
v2: Reworded the getter kerneldoc (Andrea Righi).
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Diffstat (limited to 'samples/bpf/net_shared.h')
| -rw-r--r-- | samples/bpf/net_shared.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/samples/bpf/net_shared.h b/samples/bpf/net_shared.h new file mode 100644 index 000000000..88cc52461 --- /dev/null +++ b/samples/bpf/net_shared.h @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef _NET_SHARED_H +#define _NET_SHARED_H + +#define AF_INET 2 +#define AF_INET6 10 + +#define ETH_ALEN 6 +#define ETH_P_802_3_MIN 0x0600 +#define ETH_P_8021Q 0x8100 +#define ETH_P_8021AD 0x88A8 +#define ETH_P_IP 0x0800 +#define ETH_P_IPV6 0x86DD +#define ETH_P_ARP 0x0806 +#define IPPROTO_ICMPV6 58 + +#define TC_ACT_OK 0 +#define TC_ACT_SHOT 2 + +#define IFNAMSIZ 16 + +#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \ + __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#define bpf_ntohs(x) __builtin_bswap16(x) +#define bpf_htons(x) __builtin_bswap16(x) +#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \ + __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ +#define bpf_ntohs(x) (x) +#define bpf_htons(x) (x) +#else +# error "Endianness detection needs to be set up for your compiler?!" +#endif + +#endif |