qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: "Alex Bennée" <alex.bennee@linaro.org>
To: dovgaluk@ispras.ru, rth@twiddle.net, pbonzini@redhat.com
Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org,
	mttcg@listserver.greensocs.com, fred.konrad@greensocs.com,
	a.rigo@virtualopensystems.com, cota@braap.org,
	bobby.prani@gmail.com, nikunj@linux.vnet.ibm.com,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Peter Crosthwaite" <crosthwaite.peter@gmail.com>
Subject: [Qemu-devel] [PATCH v2 11/12] cpus: call cpu_update_icount on read
Date: Wed,  5 Apr 2017 14:25:02 +0100	[thread overview]
Message-ID: <20170405132503.32125-12-alex.bennee@linaro.org> (raw)
In-Reply-To: <20170405132503.32125-1-alex.bennee@linaro.org>

This ensures each time the vCPU thread reads the icount we update the
master timer_state.qemu_icount field. This way as long as updates are
in BQL protected sections (which they should be) the main-loop can
never come to update the log and find time has gone backwards.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 cpus.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/cpus.c b/cpus.c
index ff75af449a..63de033cc8 100644
--- a/cpus.c
+++ b/cpus.c
@@ -246,19 +246,17 @@ void cpu_update_icount(CPUState *cpu)
 
 int64_t cpu_get_icount_raw(void)
 {
-    int64_t icount;
     CPUState *cpu = current_cpu;
 
-    icount = atomic_read(&timers_state.qemu_icount);
     if (cpu && cpu->running) {
         if (!cpu->can_do_io) {
             fprintf(stderr, "Bad icount read\n");
             exit(1);
         }
         /* Take into account what has run */
-        icount += cpu_get_icount_executed(cpu);
+        cpu_update_icount(cpu);
     }
-    return icount;
+    return atomic_read(&timers_state.qemu_icount);
 }
 
 /* Return the virtual CPU time, based on the instruction counter.  */
-- 
2.11.0

  parent reply	other threads:[~2017-04-05 13:25 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-05 13:24 [Qemu-devel] [PATCH v2 00/12] icount and misc MTTCG fixes for 2.9-rc4 Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 01/12] scripts/qemugdb/mtree.py: fix up mtree dump Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 02/12] scripts/qemu-gdb/timers.py: new helper to dump timer state Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 03/12] scripts/replay-dump.py: replay log dumper Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 04/12] target/i386/misc_helper: wrap BQL around another IRQ generator Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 05/12] cpus: remove icount handling from qemu_tcg_cpu_thread_fn Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 06/12] cpus: check cpu->running in cpu_get_icount_raw() Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 07/12] cpus: move icount preparation out of tcg_exec_cpu Alex Bennée
2017-04-05 13:24 ` [Qemu-devel] [PATCH v2 08/12] cpus: don't credit executed instructions before they have run Alex Bennée
2017-04-05 13:25 ` [Qemu-devel] [PATCH v2 09/12] cpus: introduce cpu_update_icount helper Alex Bennée
2017-04-05 14:08   ` Paolo Bonzini
2017-04-05 14:34     ` Alex Bennée
2017-04-05 15:00       ` Paolo Bonzini
2017-04-05 13:25 ` [Qemu-devel] [PATCH v2 10/12] cpu-exec: update icount after each TB_EXIT Alex Bennée
2017-04-05 13:25 ` Alex Bennée [this message]
2017-04-05 14:07   ` [Qemu-devel] [PATCH v2 11/12] cpus: call cpu_update_icount on read Paolo Bonzini
2017-04-07 11:35     ` Alex Bennée
2017-04-07 12:19       ` Paolo Bonzini
2017-04-07 13:14         ` Alex Bennée
2017-04-07 18:42           ` Richard Henderson
2017-04-05 13:25 ` [Qemu-devel] [PATCH v2 12/12] replay: assert time only goes forward Alex Bennée
2017-04-05 13:33   ` Pavel Dovgalyuk
2017-04-05 13:49     ` Paolo Bonzini
2017-04-05 14:37       ` Alex Bennée

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170405132503.32125-12-alex.bennee@linaro.org \
    --to=alex.bennee@linaro.org \
    --cc=a.rigo@virtualopensystems.com \
    --cc=bobby.prani@gmail.com \
    --cc=cota@braap.org \
    --cc=crosthwaite.peter@gmail.com \
    --cc=dovgaluk@ispras.ru \
    --cc=fred.konrad@greensocs.com \
    --cc=mttcg@listserver.greensocs.com \
    --cc=nikunj@linux.vnet.ibm.com \
    --cc=pbonzini@redhat.com \
    --cc=peter.maydell@linaro.org \
    --cc=qemu-devel@nongnu.org \
    --cc=rth@twiddle.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).