[COMMIT seastar master] Add example for cpuset docs

[Commit Bot]

From: Kfir Gollan <kfir....@gmail.com>
Committer: Avi Kivity <a...@scylladb.com>
Branch: master

Add example for cpuset docs

---
diff --git a/src/core/reactor.cc b/src/core/reactor.cc
--- a/src/core/reactor.cc
+++ b/src/core/reactor.cc
@@ -3774,7 +3774,7 @@ reactor_options::reactor_options(program_options::option_group* parent_group)
smp_options::smp_options(program_options::option_group* parent_group)
: program_options::option_group(parent_group, "SMP options")
, smp(*this, "smp", {}, "number of threads (default: one per CPU)")
- , cpuset(*this, "cpuset", {}, "CPUs to use (in cpuset(7) format; default: all))")
+ , cpuset(*this, "cpuset", {}, "CPUs to use (in cpuset(7) list format (ex: 0,1-3,7); default: all))")
, memory(*this, "memory", std::nullopt, "memory to use, in bytes (ex: 4G) (default: all)")
, reserve_memory(*this, "reserve-memory", {}, "memory reserved to OS (if --memory not specified)")
, hugepages(*this, "hugepages", {}, "path to accessible hugetlbfs mount (typically /dev/hugepages/something)")