Re: [Qemu-devel] [PATCH v4 00/11] simplify usage of tracepoints, and connect them to logging

["Denis V. Lunev" <den@openvz.org>]

On 01/07/2016 08:04 PM, Eric Blake wrote:
> On 01/07/2016 06:55 AM, Denis V. Lunev 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.
> Stale sentence :)
>
copy/paste forever :)