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Re: [Qemu-devel] [PATCH 0/9] simplify usage of tracepoints, and connect
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 0/9] simplify usage of tracepoints, and connect them to logging |
Date: |
Sun, 25 Oct 2015 13:57:03 +0000 |
On 25 October 2015 at 13:32, Paolo Bonzini <address@hidden> wrote:
> This series does three things:
>
> 1) add a "-trace [enable=]foo" option to enable one or more trace
> events, and a "-trace help" option to show the list of tracepoints
> (patches 4-5)
>
> 2) change the stderr tracing backend so that it prints to the
> -D log file, and enable it by default. "-trace file=..." is
> now a synonym of -D if the log backend is enabled (patches 7-8)
>
> 3) add a "-d trace:foo" option that is a synonym for "-trace foo";
> this makes the new functionality more discoverable to people used
> to "-d", makes it available for user-mode emulation (which does
> not have -trace), and is somewhat nice if you want to enable both
> tracepoints and some other "-d" flag (patch 9). When globbing
> it is also less susceptible to unwanted shell expansion.
>
> For example, you can trace block device I/O and save the result
> to a file just by adding "-trace bdrv_aio_*,file=trace.txt", or
> correlate it to guest PCs with "-d exec,nochain,trace:bdrv_aio_*".
>
> Opinions? I would like to have this in 2.5 if there is agreement.
Have you done any performance testing to check that we don't have
previously-nopped-out tracepoints in hot paths that now result in
real code being generated?
thanks
-- PMM
- [Qemu-devel] [PATCH 1/9] trace: fix documentation, (continued)
- [Qemu-devel] [PATCH 1/9] trace: fix documentation, Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 2/9] trace: split trace_init_events out of trace_init_backends, Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 3/9] trace: split trace_init_file out of trace_init_backends, Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 5/9] trace: add "-trace help", Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 4/9] trace: add "-trace enable=...", Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 6/9] log: do not unnecessarily include qom/cpu.h, Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 7/9] trace: convert stderr backend to log, Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 8/9] trace: switch default backend to "log", Paolo Bonzini, 2015/10/25
- [Qemu-devel] [PATCH 9/9] log: add "-d trace:PATTERN", Paolo Bonzini, 2015/10/25
- Re: [Qemu-devel] [PATCH 0/9] simplify usage of tracepoints, and connect them to logging,
Peter Maydell <=
- Re: [Qemu-devel] [PATCH 0/9] simplify usage of tracepoints, and connect them to logging, Christian Borntraeger, 2015/10/25
- Re: [Qemu-devel] [PATCH 0/9] simplify usage of tracepoints, and connect them to logging, Christian Borntraeger, 2015/10/25