diff options
| author | Sergey Fedorov <serge.fdrv@gmail.com> | 2016-07-15 20:58:44 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-13 19:08:42 +0200 |
| commit | 118b07308a8cedc16ef63d7ab243a95f1701db40 (patch) | |
| tree | ac1e17b27cab6c16018a3409a81d8e31c0472c18 /translate-all.c | |
| parent | 89a16b1e4294e3664667a151c2f70c84dfac6fd9 (diff) | |
| download | qemu-118b07308a8cedc16ef63d7ab243a95f1701db40.tar.gz | |
tcg: Prepare safe access to tb_flushed out of tb_lock
Ensure atomicity and ordering of CPU's 'tb_flushed' access for future
translation block lookup out of 'tb_lock'.
This field can only be touched from another thread by tb_flush() in user
mode emulation. So the only access to be sequential atomic is:
* a single write in tb_flush();
* reads/writes out of 'tb_lock'.
In future, before enabling MTTCG in system mode, tb_flush() must be safe
and this field becomes unnecessary.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20160715175852.30749-5-sergey.fedorov@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'translate-all.c')
| -rw-r--r-- | translate-all.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/translate-all.c b/translate-all.c index 77ae59d7e9..e753a50640 100644 --- a/translate-all.c +++ b/translate-all.c @@ -848,7 +848,6 @@ void tb_flush(CPUState *cpu) > tcg_ctx.code_gen_buffer_size) { cpu_abort(cpu, "Internal error: code buffer overflow\n"); } - tcg_ctx.tb_ctx.nb_tbs = 0; CPU_FOREACH(cpu) { int i; @@ -856,9 +855,10 @@ void tb_flush(CPUState *cpu) for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) { atomic_set(&cpu->tb_jmp_cache[i], NULL); } - cpu->tb_flushed = true; + atomic_mb_set(&cpu->tb_flushed, true); } + tcg_ctx.tb_ctx.nb_tbs = 0; qht_reset_size(&tcg_ctx.tb_ctx.htable, CODE_GEN_HTABLE_SIZE); page_flush_tb(); |