It turns out there are some 64 bit systems that have relatively low
amounts of physical memory available to them (typically CI system).
Even with swapping available a 1GB translation buffer that fills up
can put the machine under increased memory pressure. Detect these low
memory situations and reduce tb_size appropriately.
Fixes: 600e17b2615 ("accel/tcg: increase default code gen buffer size for 64
bit")
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Robert Foley <robert.fo...@linaro.org>
Cc: BALATON Zoltan <bala...@eik.bme.hu>
Cc: Christian Ehrhardt <christian.ehrha...@canonical.com>
Message-Id: <20200724064509.331-7-alex.ben...@linaro.org>
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 2afa46bd2b1..2d83013633b 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -976,7 +976,12 @@ static inline size_t size_code_gen_buffer(size_t tb_size)
{
/* Size the buffer. */
if (tb_size == 0) {
- tb_size = DEFAULT_CODE_GEN_BUFFER_SIZE;
+ size_t phys_mem = qemu_get_host_physmem();
+ if (phys_mem == 0) {
+ tb_size = DEFAULT_CODE_GEN_BUFFER_SIZE;
+ } else {
+ tb_size = MIN(DEFAULT_CODE_GEN_BUFFER_SIZE, phys_mem / 8);
+ }
}
if (tb_size < MIN_CODE_GEN_BUFFER_SIZE) {
tb_size = MIN_CODE_GEN_BUFFER_SIZE;
--
2.20.1
