Misc pull request for QEMU 7.1

[PULL 41/53] thread-posix: use monotonic clock for QemuCond and QemuSemaphore

Paolo Bonzini posted 53 patches 3 years, 8 months ago

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Maintainers: Cameron Esfahani <dirty@apple.com>, Roman Bolshakov <r.bolshakov@yadro.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Gerd Hoffmann <kraxel@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, David Hildenbrand <david@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Stefan Berger <stefanb@linux.vnet.ibm.com>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>, Aarushi Mehta <mehta.aaru20@gmail.com>, Julia Suvorova <jusual@redhat.com>, Stefano Garzarella <sgarzare@redhat.com>, Ronnie Sahlberg <ronniesahlberg@gmail.com>, Peter Lieven <pl@kamp.de>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, "Denis V. Lunev" <den@openvz.org>, Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru>, Markus Armbruster <armbru@redhat.com>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>, Laurent Vivier <laurent@vivier.eu>, "Michael S. Tsirkin" <mst@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Yanan Wang <wangyanan55@huawei.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Greg Kurz <groug@kaod.org>, Christian Schoenebeck <qemu_oss@crudebyte.com>, "Alex Bennée" <alex.bennee@linaro.org>, Peter Maydell <peter.maydell@linaro.org>, Michael Rolnik <mrolnik@gmail.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Alistair Francis <alistair@alistair23.me>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Helge Deller <deller@gmx.de>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, "Cédric Le Goater" <clg@kaod.org>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Huacai Chen <chenhuacai@kernel.org>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aurelien Jarno <aurelien@aurel32.net>, "Hervé Poussineau" <hpoussin@reactos.org>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Pavel Pisa <pisa@cmp.felk.cvut.cz>, Vikram Garhwal <fnu.vikram@xilinx.com>, Jason Wang <jasowang@redhat.com>, Subbaraya Sundeep <sundeep.lkml@gmail.com>, Havard Skinnemoen <hskinnemoen@google.com>, Tyrone Ting <kfting@nuvoton.com>, Dmitry Fleytman <dmitry.fleytman@gmail.com>, Chris Wulff <crwulff@gmail.com>, Marek Vasut <marex@denx.de>, BALATON Zoltan <balaton@eik.bme.hu>, Elena Ufimtseva <elena.ufimtseva@oracle.com>, Jagannathan Raman <jag.raman@oracle.com>, John G Johnson <john.g.johnson@oracle.com>, Alexey Kardashevskiy <aik@ozlabs.ru>, Yuval Shaia <yuval.shaia.ml@gmail.com>, Palmer Dabbelt <palmer@dabbelt.com>, Bin Meng <bin.meng@windriver.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Eric Farman <farman@linux.ibm.com>, Fabien Chouteau <chouteau@adacore.com>, Frederic Konrad <konrad.frederic@yahoo.fr>, Artyom Tarasenko <atar4qemu@gmail.com>, Alex Williamson <alex.williamson@redhat.com>, Eric Auger <eric.auger@redhat.com>, Max Filippov <jcmvbkbc@gmail.com>, Peter Xu <peterx@redhat.com>, Stefan Weil <sw@weilnetz.de>, Taylor Simpson <tsimpson@quicinc.com>, Juan Quintela <quintela@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Zhang Chen <chen.zhang@intel.com>, Li Zhijian <lizhijian@fujitsu.com>, Eric Blake <eblake@redhat.com>, Michael Roth <michael.roth@amd.com>, Konstantin Kostiuk <kkostiuk@redhat.com>, Alexander Graf <agraf@csgraf.de>, Wenchao Wang <wenchao.wang@intel.com>, Colin Xu <colin.xu@intel.com>, Marcelo Tosatti <mtosatti@redhat.com>, Kamil Rytarowski <kamil@netbsd.org>, Reinoud Zandijk <reinoud@netbsd.org>, Sunil Muthuswamy <sunilmut@microsoft.com>, Stafford Horne <shorne@gmail.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Ani Sinha <ani@anisinha.ca>, John Snow <jsnow@redhat.com>, Andrew Jeffery <andrew@aj.id.au>, Joel Stanley <joel@jms.id.au>, Alexander Bulekov <alxndr@bu.edu>, Bandan Das <bsd@redhat.com>, Darren Kenny <darren.kenny@oracle.com>, Qiuhao Li <Qiuhao.Li@outlook.com>, Corey Minyard <minyard@acm.org>, Coiby Xu <Coiby.Xu@gmail.com>

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[PULL 41/53] thread-posix: use monotonic clock for QemuCond and QemuSemaphore

Posted by Paolo Bonzini 3 years, 8 months ago

From: "Longpeng(Mike)" <longpeng2@huawei.com>

Use CLOCK_MONOTONIC, so the timeout isn't affected by changes to
the system time. It depends on the pthread_condattr_setclock(),
while some systems(e.g. mac os) does not support it, so the behavior
won't change in these systems.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Message-Id: <20220222090507.2028-3-longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build              | 11 +++++++++
 util/qemu-thread-posix.c | 53 ++++++++++++++++++++++++++++++++++------
 2 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/meson.build b/meson.build
index 526e9dc03b..6ba60950c8 100644
--- a/meson.build
+++ b/meson.build
@@ -1780,6 +1780,17 @@ config_host_data.set('CONFIG_PTHREAD_SETNAME_NP_WO_TID', cc.links(gnu_source_pre
     pthread_create(&thread, 0, f, 0);
     return 0;
   }''', dependencies: threads))
+config_host_data.set('CONFIG_PTHREAD_CONDATTR_SETCLOCK', cc.links(gnu_source_prefix + '''
+  #include <pthread.h>
+  #include <time.h>
+
+  int main(void)
+  {
+    pthread_condattr_t attr
+    pthread_condattr_init(&attr);
+    pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
+    return 0;
+  }''', dependencies: threads))
 
 config_host_data.set('CONFIG_SIGNALFD', cc.links(gnu_source_prefix + '''
   #include <sys/signalfd.h>
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 1ad2503607..f6a34eed2f 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -38,12 +38,20 @@ static void error_exit(int err, const char *msg)
     abort();
 }
 
+static inline clockid_t qemu_timedwait_clockid(void)
+{
+#ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
+    return CLOCK_MONOTONIC;
+#else
+    return CLOCK_REALTIME;
+#endif
+}
+
 static void compute_abs_deadline(struct timespec *ts, int ms)
 {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    ts->tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000;
-    ts->tv_sec = tv.tv_sec + ms / 1000;
+    clock_gettime(qemu_timedwait_clockid(), ts);
+    ts->tv_nsec += (ms % 1000) * 1000000;
+    ts->tv_sec += ms / 1000;
     if (ts->tv_nsec >= 1000000000) {
         ts->tv_sec++;
         ts->tv_nsec -= 1000000000;
@@ -147,11 +155,27 @@ void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line)
 
 void qemu_cond_init(QemuCond *cond)
 {
+    pthread_condattr_t attr;
     int err;
 
-    err = pthread_cond_init(&cond->cond, NULL);
-    if (err)
+    err = pthread_condattr_init(&attr);
+    if (err) {
         error_exit(err, __func__);
+    }
+#ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
+    err = pthread_condattr_setclock(&attr, qemu_timedwait_clockid());
+    if (err) {
+        error_exit(err, __func__);
+    }
+#endif
+    err = pthread_cond_init(&cond->cond, &attr);
+    if (err) {
+        error_exit(err, __func__);
+    }
+    err = pthread_condattr_destroy(&attr);
+    if (err) {
+        error_exit(err, __func__);
+    }
     cond->initialized = true;
 }
 
@@ -217,16 +241,31 @@ bool qemu_cond_timedwait_impl(QemuCond *cond, QemuMutex *mutex, int ms,
 
 void qemu_sem_init(QemuSemaphore *sem, int init)
 {
+    pthread_condattr_t attr;
     int rc;
 
     rc = pthread_mutex_init(&sem->lock, NULL);
     if (rc != 0) {
         error_exit(rc, __func__);
     }
-    rc = pthread_cond_init(&sem->cond, NULL);
+    rc = pthread_condattr_init(&attr);
     if (rc != 0) {
         error_exit(rc, __func__);
     }
+#ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK
+    rc = pthread_condattr_setclock(&attr, qemu_timedwait_clockid());
+    if (rc != 0) {
+        error_exit(rc, __func__);
+    }
+#endif
+    rc = pthread_cond_init(&sem->cond, &attr);
+    if (rc != 0) {
+        error_exit(rc, __func__);
+    }
+    rc = pthread_condattr_destroy(&attr);
+    if (rc < 0) {
+        error_exit(rc, __func__);
+    }
     if (init < 0) {
         error_exit(EINVAL, __func__);
     }
-- 
2.35.1