ceph/src/seastar/include/seastar/core/smp_options.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright 2022 ScyllaDB
  20  */
  21
  22 #pragma once
  23
  24 #include <seastar/util/program-options.hh>
  25
  26 /// \file
  27
  28 namespace seastar {
  29
  30 enum class memory_allocator {
  31     /// Seastar's own allocator, optimized for its shard-per core design.
  32     /// Strongly recommended for most seastar apps.
  33     seastar,
  34     /// The standard allocator from libc.
  35     /// Useful when writing seastar-based tool apps that want to
  36     /// minimize their footprint on the system they run on.
  37     standard,
  38 };
  39
  40 /// Configuration for the multicore aspect of seastar.
  41 struct smp_options : public program_options::option_group {
  42     /// Number of threads (default: one per CPU).
  43     program_options::value<unsigned> smp;
  44     /// CPUs to use (in cpuset(7) format; default: all)).
  45     program_options::value<resource::cpuset> cpuset;
  46     /// Memory to use, in bytes (ex: 4G) (default: all).
  47     program_options::value<std::string> memory;
  48     /// Memory reserved to OS (if \ref memory not specified).
  49     program_options::value<std::string> reserve_memory;
  50     /// Path to accessible hugetlbfs mount (typically /dev/hugepages/something).
  51     program_options::value<std::string> hugepages;
  52     /// Lock all memory (prevents swapping).
  53     program_options::value<bool> lock_memory;
  54     /// Pin threads to their cpus (disable for overprovisioning).
  55     ///
  56     /// Default: \p true.
  57     program_options::value<bool> thread_affinity;
  58     /// \brief Number of IO queues.
  59     ///
  60     /// Each IO unit will be responsible for a fraction of the IO requests.
  61     /// Defaults to the number of threads
  62     /// \note Unused when seastar is compiled without \p HWLOC support.
  63     program_options::value<unsigned> num_io_queues;
  64     /// \brief Number of IO groups.
  65     ///
  66     /// Each IO group will be responsible for a fraction of the IO requests.
  67     /// Defaults to the number of NUMA nodes
  68     /// \note Unused when seastar is compiled without \p HWLOC support.
  69     program_options::value<unsigned> num_io_groups;
  70     /// Path to a YAML file describing the characteristics of the I/O Subsystem.
  71     program_options::value<std::string> io_properties_file;
  72     /// A YAML string describing the characteristics of the I/O Subsystem.
  73     program_options::value<std::string> io_properties;
  74     /// Enable mbind.
  75     ///
  76     /// Default: \p true.
  77     program_options::value<bool> mbind;
  78     /// Enable workaround for glibc/gcc c++ exception scalablity problem.
  79     ///
  80     /// Default: \p true.
  81     /// \note Unused when seastar is compiled without the exception scaling support.
  82     program_options::value<bool> enable_glibc_exception_scaling_workaround;
  83     /// If some CPUs are found not to have any local NUMA nodes, allow assigning
  84     /// them to remote ones.
  85     /// \note Unused when seastar is compiled without \p HWLOC support.
  86     program_options::value<bool> allow_cpus_in_remote_numa_nodes;
  87
  88     /// Memory allocator to use.
  89     ///
  90     /// The following options only have effect if the \ref memory_allocator::seastar is used:
  91     /// * \ref smp_options::memory
  92     /// * \ref smp_options::reserve_memory
  93     /// * \ref smp_options::hugepages
  94     /// * \ref smp_options::mbind
  95     /// * \ref reactor_options::heapprof
  96     /// * \ref reactor_options::abort_on_seastar_bad_alloc
  97     /// * \ref reactor_options::dump_memory_diagnostics_on_alloc_failure_kind
  98     seastar::memory_allocator memory_allocator = memory_allocator::seastar;
  99
 100     /// \cond internal
 101     /// Additional memory reserved to OS (added to the default value or the value specified by \ref reserve_memory).
 102     size_t reserve_additional_memory = 0;
 103     /// \endcond
 104 public:
 105     smp_options(program_options::option_group* parent_group);
 106 };
 107
 108 }