diff options
| -rw-r--r-- | build2/b-options | 8 | ||||
| -rw-r--r-- | build2/b-options.cxx | 15 | ||||
| -rw-r--r-- | build2/b-options.ixx | 12 | ||||
| -rw-r--r-- | build2/b.cli | 10 | ||||
| -rw-r--r-- | build2/b.cxx | 2 | ||||
| -rw-r--r-- | build2/scheduler.cxx | 11 |
6 files changed, 54 insertions, 4 deletions
diff --git a/build2/b-options b/build2/b-options index c692cae..e674798 100644 --- a/build2/b-options +++ b/build2/b-options @@ -422,6 +422,12 @@ namespace build2 bool max_jobs_specified () const; + const size_t& + queue_depth () const; + + bool + queue_depth_specified () const; + const bool& serial_stop () const; @@ -495,6 +501,8 @@ namespace build2 bool jobs_specified_; size_t max_jobs_; bool max_jobs_specified_; + size_t queue_depth_; + bool queue_depth_specified_; bool serial_stop_; bool no_column_; bool no_line_; diff --git a/build2/b-options.cxx b/build2/b-options.cxx index d89adcf..d31868c 100644 --- a/build2/b-options.cxx +++ b/build2/b-options.cxx @@ -578,6 +578,8 @@ namespace build2 jobs_specified_ (false), max_jobs_ (), max_jobs_specified_ (false), + queue_depth_ (4), + queue_depth_specified_ (false), serial_stop_ (), no_column_ (), no_line_ (), @@ -706,6 +708,13 @@ namespace build2 << " scheduler implementation for details." << ::std::endl; os << std::endl + << "\033[1m--queue-depth\033[0m|\033[1m-Q\033[0m \033[4mnum\033[0m The queue depth as a multiplier over the number of active" << ::std::endl + << " jobs. Normally we want a deeper queue if the jobs take" << ::std::endl + << " long (for example, compilation) and shorter if they are" << ::std::endl + << " quick (for example, simple tests). The default is 4. See" << ::std::endl + << " the build system scheduler implementation for details." << ::std::endl; + + os << std::endl << "\033[1m--serial-stop\033[0m|\033[1m-s\033[0m Run serially and stop at the first error. This mode is" << ::std::endl << " useful to investigate build failures that are caused by" << ::std::endl << " build system errors rather than compilation errors. Note" << ::std::endl @@ -801,6 +810,12 @@ namespace build2 _cli_options_map_["-J"] = &::build2::cl::thunk< options, size_t, &options::max_jobs_, &options::max_jobs_specified_ >; + _cli_options_map_["--queue-depth"] = + &::build2::cl::thunk< options, size_t, &options::queue_depth_, + &options::queue_depth_specified_ >; + _cli_options_map_["-Q"] = + &::build2::cl::thunk< options, size_t, &options::queue_depth_, + &options::queue_depth_specified_ >; _cli_options_map_["--serial-stop"] = &::build2::cl::thunk< options, bool, &options::serial_stop_ >; _cli_options_map_["-s"] = diff --git a/build2/b-options.ixx b/build2/b-options.ixx index c230f7c..6c49ede 100644 --- a/build2/b-options.ixx +++ b/build2/b-options.ixx @@ -270,6 +270,18 @@ namespace build2 return this->max_jobs_specified_; } + inline const size_t& options:: + queue_depth () const + { + return this->queue_depth_; + } + + inline bool options:: + queue_depth_specified () const + { + return this->queue_depth_specified_; + } + inline const bool& options:: serial_stop () const { diff --git a/build2/b.cli b/build2/b.cli index f1fd7dc..726f04e 100644 --- a/build2/b.cli +++ b/build2/b.cli @@ -380,6 +380,16 @@ namespace build2 on 64-bit. See the build system scheduler implementation for details." } + size_t --queue-depth|-Q = 4 + { + "<num>", + "The queue depth as a multiplier over the number of active jobs. + Normally we want a deeper queue if the jobs take long (for example, + compilation) and shorter if they are quick (for example, simple tests). + The default is 4. See the build system scheduler implementation for + details." + } + bool --serial-stop|-s { "Run serially and stop at the first error. This mode is useful to diff --git a/build2/b.cxx b/build2/b.cxx index 17a6645..60ac2f0 100644 --- a/build2/b.cxx +++ b/build2/b.cxx @@ -356,7 +356,7 @@ main (int argc, char* argv[]) fail << "invalid --max-jobs|-J value"; } - sched.startup (jobs, 1, max_jobs); + sched.startup (jobs, 1, max_jobs, jobs * ops.queue_depth ()); variable_cache_mutex_shard_size = sched.shard_size (); variable_cache_mutex_shard.reset ( diff --git a/build2/scheduler.cxx b/build2/scheduler.cxx index 05816b8..9a3003b 100644 --- a/build2/scheduler.cxx +++ b/build2/scheduler.cxx @@ -255,12 +255,17 @@ namespace build2 max_threads_ = max_threads; // This value should be proportional to the amount of hardware concurrency - // we have (no use queing things if helpers cannot keep up). Note that the - // queue entry is quite sizable. + // we have (no use queing things up if helpers cannot keep up). Note that + // the queue entry is quite sizable. + // + // The relationship is as follows: we want to have a deeper queue if the + // tasks take long (e.g., compilation) and shorter if they are quick (e.g, + // test execution). If the tasks are quick then the synchronization + // overhead required for queuing/dequeuing things starts to dominate. // task_queue_depth_ = queue_depth != 0 ? queue_depth - : max_active * sizeof (void*) * 4; + : max_active * 4; queued_task_count_.store (0, memory_order_relaxed); |