From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40561) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIbIC-0001dT-F2 for qemu-devel@nongnu.org; Tue, 03 Feb 2015 06:05:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YIbI8-0005Ss-UV for qemu-devel@nongnu.org; Tue, 03 Feb 2015 06:05:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58205) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIbI8-0005Sh-Hb for qemu-devel@nongnu.org; Tue, 03 Feb 2015 06:05:12 -0500 Message-ID: <54D0AB59.7060605@redhat.com> Date: Tue, 03 Feb 2015 12:04:57 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20150122085127.5276.53895.stgit@PASHA-ISP.def.inno> <20150122085232.5276.99646.stgit@PASHA-ISP.def.inno> <54CA086D.2060706@redhat.com> <000601d03f9f$6684bef0$338e3cd0$@Dovgaluk@ispras.ru> In-Reply-To: <000601d03f9f$6684bef0$338e3cd0$@Dovgaluk@ispras.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v8 11/21] replay: recording and replaying clock ticks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgaluk , qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, alex.bennee@linaro.org, mark.burton@greensocs.com, real@ispras.ru, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, afaerber@suse.de, fred.konrad@greensocs.com On 03/02/2015 11:51, Pavel Dovgaluk wrote: >> From: Paolo Bonzini [mailto:pbonzini@redhat.com] >> On 22/01/2015 09:52, Pavel Dovgalyuk wrote: >>> Clock ticks are considered as the sources of non-deterministic data for >>> virtual machine. This patch implements saving the clock values when they >>> are acquired (virtual, host clock, rdtsc, and some other timers). >>> When replaying the execution corresponding values are read from log and >>> transfered to the module, which wants to read the values. >>> Such a design required the clock polling to be synchronized. Sometimes >>> it is not true - e.g. when timeouts for timer lists are checked. In this case >>> we use a cached value of the clock, passing it to the client code. >>> >>> Signed-off-by: Pavel Dovgalyuk >>> --- >>> cpus.c | 3 +- >>> include/qemu/timer.h | 10 +++++ >>> qemu-timer.c | 7 ++-- >>> replay/Makefile.objs | 1 + >>> replay/replay-internal.h | 13 +++++++ >>> replay/replay-time.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++ >>> replay/replay.h | 25 ++++++++++++++ >>> stubs/replay.c | 9 +++++ >>> 8 files changed, 147 insertions(+), 5 deletions(-) >>> create mode 100755 replay/replay-time.c >>> >>> diff --git a/cpus.c b/cpus.c >>> index 8787277..01d89aa 100644 >>> --- a/cpus.c >>> +++ b/cpus.c >>> @@ -353,7 +353,8 @@ static void icount_warp_rt(void *opaque) >>> >>> seqlock_write_lock(&timers_state.vm_clock_seqlock); >>> if (runstate_is_running()) { >>> - int64_t clock = cpu_get_clock_locked(); >>> + int64_t clock = REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, >>> + cpu_get_clock_locked()); >>> int64_t warp_delta; >>> >>> warp_delta = clock - vm_clock_warp_start; >>> diff --git a/include/qemu/timer.h b/include/qemu/timer.h >>> index 0666920..0c2472c 100644 >>> --- a/include/qemu/timer.h >>> +++ b/include/qemu/timer.h >>> @@ -4,6 +4,7 @@ >>> #include "qemu/typedefs.h" >>> #include "qemu-common.h" >>> #include "qemu/notify.h" >>> +#include "replay/replay.h" >>> >>> /* timers */ >>> >>> @@ -760,6 +761,8 @@ int64_t cpu_icount_to_ns(int64_t icount); >>> /*******************************************/ >>> /* host CPU ticks (if available) */ >>> >>> +#define cpu_get_real_ticks cpu_get_real_ticks_impl >>> + >>> #if defined(_ARCH_PPC) >>> >>> static inline int64_t cpu_get_real_ticks(void) >>> @@ -913,6 +916,13 @@ static inline int64_t cpu_get_real_ticks (void) >>> } >>> #endif >>> >>> +#undef cpu_get_real_ticks >>> + >>> +static inline int64_t cpu_get_real_ticks(void) >> >> cpu_get_real_ticks should never be used. Please instead wrap >> cpu_get_ticks() with REPLAY_CLOCK. > > I don't quite understand this comment. > Do you mean that I should move REPLAY_CLOCK to the cpu_get_real_ticks usages instead of it's implementation? Only to the cpu_get_ticks usage. The others are okay. >>> +/*! Reads next clock value from the file. >>> + If clock kind read from the file is different from the parameter, >>> + the value is not used. >>> + If the parameter is -1, the clock value is read to the cache anyway. */ >> >> In what case could the clock kind not match? >> > > It was used in full version which had to skip clock from the log while loading the VM state. So can it be removed for now? Paolo >> >>> +void replay_read_next_clock(unsigned int kind); >>> + >>> /* Asynchronous events queue */ >>> > > > Pavel Dovgalyuk >