On 23/9/25 23:54, Richard Henderson wrote:
It is too easy to mis-use tb_flush(). For instance, because of the cpu argument, some parts assumed that it needed to call the global flush function for every cpu. It is easy to forget that the flush is not complete when the call returns: we have merely queued work to the cpu run loop. So: remove tb_flush and expose only the core as tb_flush__exclusive, to be used only when we are already within an exclusive context.In some cases (gdbstub, alpha, riscv, ppc spapr), we can eliminate the need for tb_flush completely. Changes for v3: - Rename to tb_flush__exclusive_or_serial; retain the serial check within, not updating to exclusive only. - Rename the existing tb_flush to queue_tb_flush; retain the sequence number check for duplicated flushes. - Drop EXCP_TB_FLUSH.
When using my split-accel branch, I had good results with v2. I'm getting crashes with v3: Termination Reason: Namespace SIGNAL, Code 4 Illegal instruction: 4 Thread 4 Crashed: 0 ??? 0x34400fb00 ??? 1 qemu-system-aarch64-unsigned 0x100fd74dc cpu_tb_exec + 160 (cpu-exec.c:441) 2 qemu-system-aarch64-unsigned 0x100fd829c cpu_loop_exec_tb + 32 (cpu-exec.c:897) [inlined] 3 qemu-system-aarch64-unsigned 0x100fd829c cpu_exec_loop + 904 (cpu-exec.c:1009) 4 qemu-system-aarch64-unsigned 0x100fd7a30 cpu_exec_setjmp + 48 (cpu-exec.c:1026) 5 qemu-system-aarch64-unsigned 0x100fd7954 cpu_exec + 496 (cpu-exec.c:1052) 6 qemu-system-aarch64-unsigned 0x100ff9bc4 tcg_cpu_exec + 44 (tcg-accel-ops.c:97) 7 qemu-system-aarch64-unsigned 0x100ffa4c4 mttcg_cpu_exec + 28 (tcg-accel-ops-mttcg.c:146) 8 qemu-system-aarch64-unsigned 0x10140bdac split_cpu_thread_routine + 540 (split-accel-ops.c:87) 9 qemu-system-aarch64-unsigned 0x10158f7e0 qemu_thread_start + 132 (qemu-thread-posix.c:393) Thread 5: 0 qemu-system-aarch64-unsigned 0x100fb04e0 tcg_out_ld + 160 (tcg-target.c.inc:1268) 1 qemu-system-aarch64-unsigned 0x100fab3f8 tcg_reg_alloc_op + 240 [inlined] 2 qemu-system-aarch64-unsigned 0x100fab3f8 tcg_gen_code + 7932 (tcg.c:7018) 3 qemu-system-aarch64-unsigned 0x100fe9e88 setjmp_gen_code + 184 (translate-all.c:257) 4 qemu-system-aarch64-unsigned 0x100fe9780 tb_gen_code + 364 (translate-all.c:324) 5 qemu-system-aarch64-unsigned 0x100fd8138 cpu_exec_loop + 548 (cpu-exec.c:980) 6 qemu-system-aarch64-unsigned 0x100fd7a30 cpu_exec_setjmp + 48 (cpu-exec.c:1026) 7 qemu-system-aarch64-unsigned 0x100fd7954 cpu_exec + 496 (cpu-exec.c:1052) 8 qemu-system-aarch64-unsigned 0x100ff9bc4 tcg_cpu_exec + 44 (tcg-accel-ops.c:97) 9 qemu-system-aarch64-unsigned 0x100ffa4c4 mttcg_cpu_exec + 28 (tcg-accel-ops-mttcg.c:146) 10 qemu-system-aarch64-unsigned 0x10140bdac split_cpu_thread_routine + 540 (split-accel-ops.c:87) 11 qemu-system-aarch64-unsigned 0x10158f7e0 qemu_thread_start + 132 (qemu-thread-posix.c:393)
