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-rw-r--r--tcg/region.c27
1 files changed, 12 insertions, 15 deletions
diff --git a/tcg/region.c b/tcg/region.c
index 478ec05..7ea0b37 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -422,7 +422,7 @@ void tcg_region_reset_all(void)
tcg_region_tree_reset_all();
}
-static size_t tcg_n_regions(size_t tb_size, unsigned max_cpus)
+static size_t tcg_n_regions(size_t tb_size, unsigned max_threads)
{
#ifdef CONFIG_USER_ONLY
return 1;
@@ -431,24 +431,25 @@ static size_t tcg_n_regions(size_t tb_size, unsigned max_cpus)
/*
* It is likely that some vCPUs will translate more code than others,
- * so we first try to set more regions than max_cpus, with those regions
+ * so we first try to set more regions than threads, with those regions
* being of reasonable size. If that's not possible we make do by evenly
* dividing the code_gen_buffer among the vCPUs.
+ *
+ * Use a single region if all we have is one vCPU thread.
*/
- /* Use a single region if all we have is one vCPU thread */
- if (max_cpus == 1 || !qemu_tcg_mttcg_enabled()) {
+ if (max_threads == 1) {
return 1;
}
/*
- * Try to have more regions than max_cpus, with each region being >= 2 MB.
+ * Try to have more regions than threads, with each region being >= 2 MB.
* If we can't, then just allocate one region per vCPU thread.
*/
n_regions = tb_size / (2 * MiB);
- if (n_regions <= max_cpus) {
- return max_cpus;
+ if (n_regions <= max_threads) {
+ return max_threads;
}
- return MIN(n_regions, max_cpus * 8);
+ return MIN(n_regions, max_threads * 8);
#endif
}
@@ -731,11 +732,7 @@ static int alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
* and then assigning regions to TCG threads so that the threads can translate
* code in parallel without synchronization.
*
- * In system-mode the number of TCG threads is bounded by max_cpus, so we use at
- * least max_cpus regions in MTTCG. In !MTTCG we use a single region.
- * Note that the TCG options from the command-line (i.e. -accel accel=tcg,[...])
- * must have been parsed before calling this function, since it calls
- * qemu_tcg_mttcg_enabled().
+ * In system-mode the number of TCG threads is bounded by max_threads,
*
* In user-mode we use a single region. Having multiple regions in user-mode
* is not supported, because the number of vCPU threads (recall that each thread
@@ -749,7 +746,7 @@ static int alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
* in practice. Multi-threaded guests share most if not all of their translated
* code, which makes parallel code generation less appealing than in system-mode
*/
-void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus)
+void tcg_region_init(size_t tb_size, int splitwx, unsigned max_threads)
{
const size_t page_size = qemu_real_host_page_size();
size_t region_size;
@@ -787,7 +784,7 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus)
* As a result of this we might end up with a few extra pages at the end of
* the buffer; we will assign those to the last region.
*/
- region.n = tcg_n_regions(tb_size, max_cpus);
+ region.n = tcg_n_regions(tb_size, max_threads);
region_size = tb_size / region.n;
region_size = QEMU_ALIGN_DOWN(region_size, page_size);