----- Original Message ----- > From: "Richard Henderson" <r...@twiddle.net> > To: "Paolo Bonzini" <pbonz...@redhat.com>, qemu-devel@nongnu.org > Cc: "serge fdrv" <serge.f...@gmail.com>, c...@braap.org, "alex bennee" > <alex.ben...@linaro.org>, "sergey fedorov" > <sergey.fedo...@linaro.org> > Sent: Friday, September 23, 2016 8:06:09 PM > Subject: Re: [Qemu-devel] [PATCH 15/16] tcg: Make tb_flush() thread safe > > On 09/23/2016 12:31 AM, Paolo Bonzini wrote: > > + unsigned tb_flush_req = (unsigned) (uintptr_t) data; > > Extra cast? > > > - tcg_ctx.tb_ctx.tb_flush_count++; > > + atomic_inc(&tcg_ctx.tb_ctx.tb_flush_count); > > Since this is the only place this value is incremented, and we're under a > lock, > it should be cheaper to use > > atomic_mb_set(&tcg_ctx.tb_ctx.tb_flush_count, tb_flush_req + 1);
atomic_set will do even. Though it's not really a fast path, which is why I went for atomic_inc. > > + uintptr_t tb_flush_req = (uintptr_t) > > + atomic_read(&tcg_ctx.tb_ctx.tb_flush_count); > > Extra cast? Yeah. Paolo > That said, it's correct as-is so, > > Reviewed-by: Richard Henderson <r...@twiddle.net> > > > r~ >
