diff options
| author | Alex Bennée <alex.bennee@linaro.org> | 2020-02-28 19:24:15 +0000 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2020-02-28 17:43:31 -0800 |
| commit | 600e17b261555c56a048781b8dd5ba3985650013 (patch) | |
| tree | a917d7a99cb61a5073568c67feec9aa7ec74ae32 /accel | |
| parent | 21f2f447ad28d099d3ac5adc8ffe8eeaa56604f4 (diff) | |
| download | qemu-600e17b261555c56a048781b8dd5ba3985650013.zip | |
accel/tcg: increase default code gen buffer size for 64 bit
While 32mb is certainly usable a full system boot ends up flushing the
codegen buffer nearly 100 times. Increase the default on 64 bit hosts
to take advantage of all that spare memory. After this change I can
boot my tests system without any TB flushes.
As we usually run more CONFIG_USER binaries at a time in typical usage
we aren't quite as profligate for user-mode code generation usage. We
also bring the static code gen defies to the same place to keep all
the reasoning in the comments together.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-Id: <20200228192415.19867-5-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/translate-all.c | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 4ce5d1b393..78914154bf 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -892,15 +892,6 @@ static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1, } } -#if defined(CONFIG_USER_ONLY) && TCG_TARGET_REG_BITS == 32 -/* - * For user mode on smaller 32 bit systems we may run into trouble - * allocating big chunks of data in the right place. On these systems - * we utilise a static code generation buffer directly in the binary. - */ -#define USE_STATIC_CODE_GEN_BUFFER -#endif - /* Minimum size of the code gen buffer. This number is randomly chosen, but not so small that we can't have a fair number of TB's live. */ #define MIN_CODE_GEN_BUFFER_SIZE (1 * MiB) @@ -929,7 +920,33 @@ static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1, # define MAX_CODE_GEN_BUFFER_SIZE ((size_t)-1) #endif +#if TCG_TARGET_REG_BITS == 32 #define DEFAULT_CODE_GEN_BUFFER_SIZE_1 (32 * MiB) +#ifdef CONFIG_USER_ONLY +/* + * For user mode on smaller 32 bit systems we may run into trouble + * allocating big chunks of data in the right place. On these systems + * we utilise a static code generation buffer directly in the binary. + */ +#define USE_STATIC_CODE_GEN_BUFFER +#endif +#else /* TCG_TARGET_REG_BITS == 64 */ +#ifdef CONFIG_USER_ONLY +/* + * As user-mode emulation typically means running multiple instances + * of the translator don't go too nuts with our default code gen + * buffer lest we make things too hard for the OS. + */ +#define DEFAULT_CODE_GEN_BUFFER_SIZE_1 (128 * MiB) +#else +/* + * We expect most system emulation to run one or two guests per host. + * Users running large scale system emulation may want to tweak their + * runtime setup via the tb-size control on the command line. + */ +#define DEFAULT_CODE_GEN_BUFFER_SIZE_1 (1 * GiB) +#endif +#endif #define DEFAULT_CODE_GEN_BUFFER_SIZE \ (DEFAULT_CODE_GEN_BUFFER_SIZE_1 < MAX_CODE_GEN_BUFFER_SIZE \ |