diff options
Diffstat (limited to 'tcg/region.c')
-rw-r--r-- | tcg/region.c | 27 |
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); |