From: Stefan Hajnoczi <stefanha@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: Re: [Qemu-devel] [Qemu-block] [PATCH 17/17] block: make accounting thread-safe
Date: Fri, 5 May 2017 13:56:09 +0100 [thread overview]
Message-ID: <20170505125609.GC11350@stefanha-x1.localdomain> (raw)
In-Reply-To: <20170420120058.28404-18-pbonzini@redhat.com>
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On Thu, Apr 20, 2017 at 02:00:58PM +0200, Paolo Bonzini wrote:
> I'm not trying too hard yet. Later, with multiqueue support,
> this may cause cacheline bouncing.
This patch calls qemu_clock_get_ns() within a spinlock region. It's
probably just a memory load, rdtsc, and some math but more heavy-weight
code paths are possible too.
Taking the clock reading outside the lock region should be fine and
reduces the chance of contention.
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next prev parent reply other threads:[~2017-05-05 12:56 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-20 12:00 [Qemu-devel] [PATCH for 2.10 00/17] Block layer thread safety, part 1 Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 01/17] block: access copy_on_read with atomic ops Paolo Bonzini
2017-05-04 11:15 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-05-04 11:51 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 02/17] block: access quiesce_counter " Paolo Bonzini
2017-05-04 12:33 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 03/17] block: access io_limits_disabled " Paolo Bonzini
2017-05-04 12:38 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 04/17] block: access serialising_in_flight " Paolo Bonzini
2017-05-04 12:39 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 05/17] block: access wakeup " Paolo Bonzini
2017-05-04 6:39 ` Fam Zheng
2017-05-04 7:12 ` Paolo Bonzini
2017-05-04 12:47 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 06/17] block: access io_plugged " Paolo Bonzini
2017-05-04 12:48 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 07/17] throttle-groups: do not use qemu_co_enter_next Paolo Bonzini
2017-05-04 13:27 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 08/17] throttle-groups: protect throttled requests with a CoMutex Paolo Bonzini
2017-05-04 6:57 ` Fam Zheng
2017-05-04 13:56 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 09/17] util: add stats64 module Paolo Bonzini
2017-05-04 7:19 ` Fam Zheng
2017-05-04 7:24 ` Paolo Bonzini
2017-05-04 7:36 ` Fam Zheng
2017-05-04 7:38 ` Paolo Bonzini
2017-05-04 8:55 ` [Qemu-devel] [Qemu-block] " Roman Kagan
2017-05-04 9:46 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 10/17] block: use Stat64 for wr_highest_offset Paolo Bonzini
2017-05-04 14:02 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 11/17] block: access write_gen with atomics Paolo Bonzini
2017-05-04 14:04 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 12/17] block: protect tracked_requests and flush_queue with reqs_lock Paolo Bonzini
2017-05-04 7:30 ` Fam Zheng
2017-05-04 8:35 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 13/17] coroutine-lock: introduce qemu_co_mutex_lock_unlock Paolo Bonzini
2017-05-04 7:39 ` Fam Zheng
2017-05-04 9:47 ` Paolo Bonzini
2017-05-04 9:52 ` Paolo Bonzini
2017-05-04 14:12 ` Stefan Hajnoczi
2017-05-04 16:17 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 14/17] block: optimize access to reqs_lock Paolo Bonzini
2017-05-04 14:59 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-05-04 16:06 ` Paolo Bonzini
2017-05-05 10:25 ` Stefan Hajnoczi
2017-05-05 10:45 ` Paolo Bonzini
2017-05-08 16:21 ` Stefan Hajnoczi
2017-05-08 16:30 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 15/17] block: introduce dirty_bitmap_mutex Paolo Bonzini
2017-05-04 7:55 ` Fam Zheng
2017-05-04 9:57 ` Paolo Bonzini
2017-04-20 12:00 ` [Qemu-devel] [PATCH 16/17] block: protect modification of dirty bitmaps with a mutex Paolo Bonzini
2017-04-20 14:42 ` Eric Blake
2017-05-04 8:05 ` Fam Zheng
2017-05-04 10:05 ` Paolo Bonzini
2017-05-05 10:36 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2017-05-05 10:47 ` Paolo Bonzini
2017-05-08 16:17 ` Stefan Hajnoczi
2017-04-20 12:00 ` [Qemu-devel] [PATCH 17/17] block: make accounting thread-safe Paolo Bonzini
2017-05-05 12:56 ` Stefan Hajnoczi [this message]
2017-04-20 12:40 ` [Qemu-devel] [PATCH for 2.10 00/17] Block layer thread safety, part 1 no-reply
2017-04-20 12:42 ` no-reply
2017-05-02 15:42 ` Paolo Bonzini
2017-05-04 8:09 ` Fam Zheng
2017-05-05 13:01 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
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