accel/tcg: Use more accurate max_insns for tb_overflow

Write back the number of insns that we attempt to translate,
so that if we longjmp out we have a more accurate limit for
the next attempt.  This results in fewer restarts when some
limit is consumed by few instructions.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index f56da8ea306ae884e82d3be3dcb002ce6ae5f27a..d0babfea8859af8d5128a35ebb79858a8ffc1476 100644 (file)
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -78,7 +78,7 @@ void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns,
     plugin_enabled = plugin_gen_tb_start(cpu, db, cflags & CF_MEMI_ONLY);
 
     while (true) {
-        db->num_insns++;
+        *max_insns = ++db->num_insns;
         ops->insn_start(db, cpu);
         tcg_debug_assert(db->is_jmp == DISAS_NEXT);  /* no early exit */