diff options
| author | Simon Marlow <marlowsd@gmail.com> | 2016-04-09 20:45:50 +0100 |
|---|---|---|
| committer | Simon Marlow <smarlow@fb.com> | 2016-05-04 05:30:30 -0700 |
| commit | 76ee260778991367b8dbf07ecf7afd31f826c824 (patch) | |
| tree | fbddddf878413dab3c01abf8108c26d2bd20db4c /includes | |
| parent | f9d93751126e58fb990335095e02fd81a3595fde (diff) | |
| download | haskell-76ee260778991367b8dbf07ecf7afd31f826c824.tar.gz | |
Allow limiting the number of GC threads (+RTS -qn<n>)
This allows the GC to use fewer threads than the number of capabilities.
At each GC, we choose some of the capabilities to be "idle", which means
that the thread running on that capability (if any) will sleep for the
duration of the GC, and the other threads will do its work. We choose
capabilities that are already idle (if any) to be the idle capabilities.
The idea is that this helps in the following situation:
* We want to use a large -N value so as to make use of hyperthreaded
cores
* We use a large heap size, so GC is infrequent
* But we don't want to use all -N threads in the GC, because that
thrashes the memory too much.
See docs for usage.
Diffstat (limited to 'includes')
| -rw-r--r-- | includes/rts/Flags.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/includes/rts/Flags.h b/includes/rts/Flags.h index 9321b4d160..16417ce34e 100644 --- a/includes/rts/Flags.h +++ b/includes/rts/Flags.h @@ -203,6 +203,10 @@ typedef struct _PAR_FLAGS { * non-load-balancing parallel GC. * (zero disables) */ + nat parGcThreads; + /* Use this many threads for parallel + * GC (default: use all nNodes). */ + rtsBool setAffinity; /* force thread affinity with CPUs */ } PAR_FLAGS; #endif /* THREADED_RTS */ |