From: Paolo Bonzini <pbonzini@redhat.com>
To: liu ping fan <qemulist@gmail.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
qemu-devel@nongnu.org, David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH 08/12] qemu-thread: report RCU quiescent states
Date: Thu, 16 May 2013 10:43:50 +0200 [thread overview]
Message-ID: <51949C46.8000001@redhat.com> (raw)
In-Reply-To: <CAJnKYQ=oW0LiYZpWsX-cFePkuxL7ZTbjjbyrzyXwr_4S0KK_AQ@mail.gmail.com>
Il 16/05/2013 10:33, liu ping fan ha scritto:
>> > +Luckily, in most cases no manual annotation is needed, because waiting
>> > +on condition variables (qemu_cond_wait), semaphores (qemu_sem_wait,
>> > +qemu_sem_timedwait) or events (qemu_event_wait) implicitly marks the thread
>> > +as quiescent for the whole duration of the wait. (There is an exception
>> > +for semaphore waits with a zero timeout).
>> > +
> Why not the same rule for zero timeout?
>
Because they are not really doing synchronization, they are basically an
"atomic_dec_if_not_zero" on the semaphore count.
Paolo
next prev parent reply other threads:[~2013-05-16 8:44 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-15 15:48 [Qemu-devel] [RFC PATCH 00/12] RCU implementation for QEMU Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 01/12] add a header file for atomic operations Paolo Bonzini
2013-05-15 16:11 ` Peter Maydell
2013-05-15 15:48 ` [Qemu-devel] [PATCH 02/12] qemu-thread: add QemuEvent Paolo Bonzini
2013-05-16 10:15 ` Stefan Hajnoczi
2013-05-16 10:49 ` Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 03/12] rcu: add rcu library Paolo Bonzini
2013-05-16 11:46 ` Stefan Hajnoczi
2013-05-17 4:36 ` liu ping fan
2013-05-17 7:08 ` liu ping fan
2013-05-17 7:35 ` Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 04/12] qemu-thread: register threads with RCU Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 05/12] rcu: add call_rcu Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 06/12] rcu: add rcutorture Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 07/12] rcu: allow nested calls to rcu_thread_offline/rcu_thread_online Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 08/12] qemu-thread: report RCU quiescent states Paolo Bonzini
2013-05-16 8:33 ` liu ping fan
2013-05-16 8:43 ` Paolo Bonzini [this message]
2013-05-15 15:48 ` [Qemu-devel] [PATCH 09/12] event loop: " Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 10/12] cpus: " Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 11/12] block: " Paolo Bonzini
2013-05-15 15:48 ` [Qemu-devel] [PATCH 12/12] migration: " Paolo Bonzini
2013-05-15 16:03 ` [Qemu-devel] [RFC PATCH 00/12] RCU implementation for QEMU Peter Maydell
2013-05-15 16:17 ` Paolo Bonzini
2013-05-15 16:16 ` Peter Maydell
2013-05-15 16:19 ` Paolo Bonzini
2013-05-15 19:28 ` Peter Maydell
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=51949C46.8000001@redhat.com \
--to=pbonzini@redhat.com \
--cc=david@gibson.dropbear.id.au \
--cc=jan.kiszka@siemens.com \
--cc=qemu-devel@nongnu.org \
--cc=qemulist@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.