diff options
| author | Lasse Collin <lasse.collin@tukaani.org> | 2022-04-14 12:59:09 +0300 |
|---|---|---|
| committer | Lasse Collin <lasse.collin@tukaani.org> | 2022-04-14 13:00:40 +0300 |
| commit | 0adc13bfe32c14f3e4c6ce9f2d4fdf4112ab53f4 (patch) | |
| tree | 3be604a3828ab11f6286340bec3df3a5ddbe946a /src/xz/hardware.c | |
| parent | xz: Changes to --memlimit-compress and --no-adjust. (diff) | |
| download | xz-0adc13bfe32c14f3e4c6ce9f2d4fdf4112ab53f4.tar.xz | |
xz: Make -T0 use multithreaded mode on single-core systems.
The main problem withi the old behavior is that the compressed
output is different on single-core systems vs. multicore systems.
This commit fixes it by making -T0 one thread in multithreaded mode
on single-core systems.
The downside of this is that it uses more memory. However, if
--memlimit-compress is used, xz can (thanks to the previous commit)
drop to the single-threaded mode still.
Diffstat (limited to 'src/xz/hardware.c')
| -rw-r--r-- | src/xz/hardware.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/xz/hardware.c b/src/xz/hardware.c index d45d6ade..18eee7ec 100644 --- a/src/xz/hardware.c +++ b/src/xz/hardware.c @@ -17,6 +17,10 @@ /// the --threads=NUM command line option. static uint32_t threads_max = 1; +/// True when the number of threads is automatically determined based +/// on the available hardware threads. +static bool threads_are_automatic = false; + /// Memory usage limit for compression static uint64_t memlimit_compress = 0; @@ -48,6 +52,8 @@ hardware_threads_set(uint32_t n) { if (n == 0) { // Automatic number of threads was requested. + threads_are_automatic = true; + // If threading support was enabled at build time, // use the number of available CPU cores. Otherwise // use one thread since disabling threading support @@ -61,6 +67,7 @@ hardware_threads_set(uint32_t n) #endif } else { threads_max = n; + threads_are_automatic = false; } return; @@ -74,6 +81,13 @@ hardware_threads_get(void) } +extern bool +hardware_threads_is_mt(void) +{ + return threads_max > 1 || threads_are_automatic; +} + + extern void hardware_memlimit_set(uint64_t new_memlimit, bool set_compress, bool set_decompress, bool set_mtdec, |