On 15/02/2017 13:45, Pavel Dovgalyuk wrote: >> From: Paolo Bonzini [mailto:paolo.bonz...@gmail.com] On Behalf Of Paolo >> Bonzini >> On 29/01/2017 22:09, Paolo Bonzini wrote: >>> The series includes three parts: >>> >>> 1-2: fix two bugs, the first one pretty bad, the second seems >>> to be theoretical only. >>> >>> 3-5: simplify cpu_exec. This builds on Sergey's conversion >>> of cpu_exec to a simple top-down logic, making the phases >>> clearer and saving on the cost of siglongjmp in the meanwhile. >> >> I'll include these five in my next pull request. Review for patch 6 is >> welcome! > > I've tested all 7 and briefly looked at their code. > Do you need official reviewed-by?
No, but for patch 6 specifically, I would like more than one review. :) Paolo > Pavel Dovgalyuk >> >>> 6-7: these are intended to be a base for Pavel's record/replay >>> fixes. The main thing I noticed while reviewing is that icount >>> is redoing (with u16.high) a lot of things that tcg_exit_req is >>> doing too. This is because, at the time icount was introduced, >>> tcg_exit_req didn't exist and QEMU instead unwound chained TBs >>> through POSIX signals. But now we have essentially two ways to >>> do the same thing with subtly different invariants or downright >>> bugs (such as the one fixed by patch 1). Patch 6 therefore >>> unifies tcg_exit_req and the icount interrupt flag. It saves a >>> handful of instructions per TB in icount mode and generally >>> makes icount mode "less special", which is a good thing since >>> no one seems to understand it well. Patch 7 then removes another >>> EXCP_INTERRUPT/cpu_loop_exit pair; by exiting to main loop simply >>> through cpu->exit_request, hopefully it fixes one of the issues that >>> Pavel was seeing. >>> >>> For now I've tested this only on an aarch64 Linux image (with >>> and without -icount). Thanks, >>> >>> Paolo >>> >>> Paolo Bonzini (7): >>> cpu-exec: fix jmp_first out-of-bounds access with icount >>> cpu-exec: tighten barrier on TCG_EXIT_REQUESTED >>> cpu-exec: avoid cpu_loop_exit in cpu_handle_interrupt >>> cpu-exec: avoid repeated sigsetjmp on interrupts >>> cpu-exec: remove outermost infinite loop >>> cpu-exec: unify icount_decr and tcg_exit_req >>> cpu-exec: centralize exiting to the main loop >>> >>> cpu-exec.c | 153 >>> +++++++++++++++++++++------------------------- >>> include/exec/exec-all.h | 1 + >>> include/exec/gen-icount.h | 53 ++++++++-------- >>> include/qom/cpu.h | 15 +++-- >>> qom/cpu.c | 2 +- >>> tcg/tcg.h | 1 - >>> translate-all.c | 2 +- >>> translate-common.c | 13 ++-- >>> 8 files changed, 109 insertions(+), 131 deletions(-) >>> >
