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authorLasse Collin <lasse.collin@tukaani.org>2022-11-19 19:06:13 +0200
committerLasse Collin <lasse.collin@tukaani.org>2022-11-19 19:06:13 +0200
commitd327743bb547a53364e5951a16e5f1663fe4b9ff (patch)
tree161f141e97f7946e05541ad92f141c3deeb2dc28 /src/xz/hardware.c
parentCMake: Adds test_memlimit to CMake tests (diff)
downloadxz-d327743bb547a53364e5951a16e5f1663fe4b9ff.tar.xz
xz: Add support --threads=+N so that -T+1 gives threaded mode.
Diffstat (limited to '')
-rw-r--r--src/xz/hardware.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/src/xz/hardware.c b/src/xz/hardware.c
index 1fdecea1..97f77f80 100644
--- a/src/xz/hardware.c
+++ b/src/xz/hardware.c
@@ -21,6 +21,10 @@ static uint32_t threads_max = 1;
/// on the available hardware threads.
static bool threads_are_automatic = false;
+/// If true, then try to use multi-threaded mode (if memlimit allows)
+/// even if only one thread was requested explicitly (-T+1).
+static bool use_mt_mode_with_one_thread = false;
+
/// Memory usage limit for compression
static uint64_t memlimit_compress = 0;
@@ -57,9 +61,16 @@ static uint64_t total_ram;
extern void
hardware_threads_set(uint32_t n)
{
+ // Reset these to false first and set them to true when appropriate.
+ threads_are_automatic = false;
+ use_mt_mode_with_one_thread = false;
+
if (n == 0) {
// Automatic number of threads was requested.
+ // If there is only one hardware thread, multi-threaded
+ // mode will still be used if memory limit allows.
threads_are_automatic = true;
+ use_mt_mode_with_one_thread = true;
// If threading support was enabled at build time,
// use the number of available CPU cores. Otherwise
@@ -72,9 +83,11 @@ hardware_threads_set(uint32_t n)
#else
threads_max = 1;
#endif
+ } else if (n == UINT32_MAX) {
+ use_mt_mode_with_one_thread = true;
+ threads_max = 1;
} else {
threads_max = n;
- threads_are_automatic = false;
}
return;
@@ -92,7 +105,7 @@ extern bool
hardware_threads_is_mt(void)
{
#ifdef MYTHREAD_ENABLED
- return threads_max > 1 || threads_are_automatic;
+ return threads_max > 1 || use_mt_mode_with_one_thread;
#else
return false;
#endif