From: Stefan Hajnoczi <stefanha@redhat.com>
To: Hollis Blanchard <hollis_blanchard@mentor.com>
Cc: pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/2] trace: separate MMIO tracepoints from TB-access tracepoints
Date: Wed, 24 Feb 2016 14:13:36 +0000 [thread overview]
Message-ID: <20160224141336.GD23533@stefanha-x1.localdomain> (raw)
In-Reply-To: <1455744555-22101-2-git-send-email-hollis_blanchard@mentor.com>
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On Wed, Feb 17, 2016 at 01:29:15PM -0800, Hollis Blanchard wrote:
> Memory accesses to code which has previously been translated into a TB show up
> in the MMIO path, so that they may invalidate the TB. It's extremely confusing
> to mix those in with device MMIOs, so split them into their own tracepoint.
>
> Signed-off-by: Hollis Blanchard <hollis_blanchard@mentor.com>
>
> ---
> It took many hours to figure out why some RAM accesses were coming through the
> MMIO path instead of being handled inline in the TBs.
>
> On IRC, Paolo expressed some concern about performance, but ultimately agreed
> that adding one conditional to an already heavy codepath wouldn't have much
> impact.
> ---
> memory.c | 25 +++++++++++++++++++++++++
> trace-events | 2 ++
> 2 files changed, 27 insertions(+)
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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next prev parent reply other threads:[~2016-02-24 14:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 21:29 [Qemu-devel] [PATCH 1/2] trace: include CPU index in trace_memory_region_ops_*() Hollis Blanchard
2016-02-17 21:29 ` [Qemu-devel] [PATCH 2/2] trace: separate MMIO tracepoints from TB-access tracepoints Hollis Blanchard
2016-02-18 18:37 ` Hollis Blanchard
2016-02-24 14:13 ` Stefan Hajnoczi [this message]
2016-03-23 16:47 ` Hollis Blanchard
2016-03-23 16:53 ` Paolo Bonzini
2016-03-23 17:16 ` Hollis Blanchard
2016-03-24 19:30 ` [Qemu-devel] io_mem_notdirty and live migration Hollis Blanchard
2016-03-24 22:01 ` Paolo Bonzini
2016-02-24 14:12 ` [Qemu-devel] [PATCH 1/2] trace: include CPU index in trace_memory_region_ops_*() Stefan Hajnoczi
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