commit 95590e24af11236ef334f6bc3e2b71404a790ddb
author Emilio G. Cota <cota@braap.org> Tue Aug 01 15:40:16 2017 -0400
committer Richard Henderson <richard.henderson@linaro.org> Fri Jun 15 08:18:42 2018 -1000
tree 76e03c0f097bd05f4921fdc6cbe067cc9e2e598e
parent faa9372c07d062eb01f9da72e3f6c0f32efffca7

translate-all: discard TB when tb_link_page returns an existing matching TB

Use the recently-gained QHT feature of returning the matching TB if it
already exists. This allows us to get rid of the lookup we perform
right after acquiring tb_lock.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/cpu-exec.c

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index d75c353..45f6ebc 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -245,10 +245,7 @@
         if (tb == NULL) {
             mmap_lock();
             tb_lock();
-            tb = tb_htable_lookup(cpu, pc, cs_base, flags, cf_mask);
-            if (likely(tb == NULL)) {
-                tb = tb_gen_code(cpu, pc, cs_base, flags, cflags);
-            }
+            tb = tb_gen_code(cpu, pc, cs_base, flags, cflags);
             tb_unlock();
             mmap_unlock();
         }
@@ -398,14 +395,7 @@
         tb_lock();
         acquired_tb_lock = true;
 
-        /* There's a chance that our desired tb has been translated while
-         * taking the locks so we check again inside the lock.
-         */
-        tb = tb_htable_lookup(cpu, pc, cs_base, flags, cf_mask);
-        if (likely(tb == NULL)) {
-            /* if no translated code available, then translate it now */
-            tb = tb_gen_code(cpu, pc, cs_base, flags, cf_mask);
-        }
+        tb = tb_gen_code(cpu, pc, cs_base, flags, cf_mask);
 
         mmap_unlock();
         /* We add the TB in the virtual pc hash table for the fast lookup */