On Fri, 26 Jan 2024 09:54:53 +0100 Pierre Gondois <pierre.gondois@xxxxxxx> wrote: > Hello Steven, > Hi Pierre, Sorry for the late reply. I've been putting out fires (you can read LWN or The Register to see what exactly I was doing). > On 1/25/24 18:10, Steven Rostedt wrote: > > On Thu, 25 Jan 2024 11:51:47 -0500 > > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > >> Now if I had had: > >> > >> trace-cmd split -i /work/traces/trace-tast.dat --top -B tast -o /tmp/trace-tast2.dat > >> > >> Then because there was a command "--top" before the -B but it had no -o > >> assigned for it, then the input_file would be considered the output file > >> and that should act like you described. > > > > Of course then things get confusing if we were to have: > > > > trace-cmd split -i /work/traces/trace-tast.dat -B foo -o /tmp/trace-foo.dat -B bar > > > > We could specify that each -B will just use the top level by default. So > > the above would create: > > > > /tmp/trace-foo.dat > > > > With the instance "foo" > > > > But the "bar" would be in: > > > > /work/traces/trace-tast.dat.bar > > > > because the top level didn't specify a -o. > > > > So to make it more specific. Each -B will default to the toplevel output > > with ".<instance>" appended to it. > > > > That is: > > > > split <top-level-commands> -B instance1 <instance1-commands> -B <instance2-commands> > > > > If a -o is specified in the <top-level-commands> it becomes the default top > > level output file. If a -o is not specified in any of the > > <instance*-commands> then, it will default to the top level output file > > with ".<instance-name>" attached to it unless it has its own -o specified. > > I also wanted to handle the case where multiple instances could be placed > in an output file. Meaning that with the patches: > - -B/--top options are parsed to select the instances to keep, > - a -o option ends the parsing of instances and place them in the given output > file. If no -o option is parsed, then the default output file or the input > file is used as a base name for the last generated output file (i.e. trace.dat.1 > if no input file is specified) OK, I see what you want. You want to be able to have multiple buffers in a single file. > > --- > > For example, with a trace recorded with: > $ trace-cmd record -e sched_wakeup -B switch_instance -e sched_switch -B timer_instance -e timer > > Creating a test.dat file containing the top instance and > the switch_instance: > $ trace-cmd split --top -B switch_instance -o test.dat > > Creating a test.dat file containing the switch_instance as > the top instance, and the initial top instance as an instance > named 'old_top': > $ trace-cmd split -B switch_instance --top=old_top -o test.dat > > Splitting all instances in different .dat files: > $ trace-cmd split --top -o top.dat -B switch_instance -o switch.dat -B timer_instance -o timer.dat > > And by default, if no -B/--top is specified for an output file, > keep all the instances (but of course all the other options provided > to the split command are applied, i.e. start/end timings): > Keep all the instances and place them in test.dat: > $ trace-cmd split -o test.dat > Keep all the instances and place them in the default file trace.dat.1: > $ trace-cmd split > > --- > > Maybe the list of generated files should be printed to avoid what happened > to you, i.e. generating files that were not expected. > I think that having a default name with a suffix being the top instance > is a good idea, but I don't think it would be possible to parse the command > line to have 2 instances in one file in such case. > > > > > For multi-file splits, it will append ".0001", ".0002", etc to that file. So what I'm thinking is that the -B buffers default to the same buffer as the top buffer unless specified differently. Here's what I think would work. We add four new options. --top -B <instance> -t -b Where --top represents the "top" instance. -B represents the <instance> -t can be used after -B to make it a top instance. -b can be used before any -B to make the top instance into its own instance. Rules: --top can not come after -B. -t must come after -B -b must come before -B There can only be one top instance, and all named instances must be unique. That is, you can't have two instances called "foo". We have: trace-cmd split <TOP_COMMANDS> <INSTANCE_COMMANDS> TOP_COMMANDS :: nil | TOP_PARAMS INSTANCE_COMMANDS :: nil | -B name INSTANCE_PARAMS INSTANCE_COMMANDS TOP_PARAMS :: nil | TOP_OPTIONS TOP_PARAMS TOP_OPTIONS :: --top | -b name | -o file INSTANCE_PARAMS :: nil | INSTANCE_OPTIONS INSTANCE_PARAMS INSTANCE_OPTIONS :: nil | -t | -o file Examples: trace-cmd split --top -B foo Will make a trace.dat.1 that has top and foo in it. trace-cmd split --top Will make a trace.dat.1 that only has the top instance trace-cmd split -B foo Will make a trace.dat.1 that only has foo in it. trace-cmd split -B foo -t Will make a trace.dat.1 that only has foo in it. It will also promote the instance foo to the top instance (it will lose its "foo" name). trace-cmd split --top -o buba.dat -B foo Will create a buba.dat that has both top and foo in it trace-cmd split --top -B foo -o buba.dat Will create a trace-dat.1 with just top in it, and buba.dat with just foo in it. trace-cmd split --top -B foo -o buba.dat -t Will create a trace-dat.1 with just top in it, and buba.dat with just foo in it (promoting foo to top instance) trace-cmd split --top -b foo -B foo -t Will make a trace.dat.1 file where the top instance becomes "foo" and the foo instance becomes the top instance. trace-cmd split -o buba.dat -B foo -t Will create just a buba.dat file with only foo in it, promoting it as the top instance. trace-cmd split -o buba.dat --top -B foo -o fooba.dat Will create a buba.dat with just the top instance in it (note --top can come before or after -o and that does not make any difference, but the order of -B and -o does matter). It will also create a fooba.dat file with just foo in it. trace-cmd split --top -B foo -t -o fooba.dat -B bar This will create a trace.dat.1 with the top instance and the bar instance, but also make a fooba.dat file with just "foo", and promoting it as the top instance. trace-cmd split --top -o buba.dat -B foo -o foobar.dat -B bar -o foobar.dat This will make two files. One with buba.dat that holds the top instance, and foobar.dat that holds both the foo and bar instances. trace-cmd split --top -o buba.dat -B foo -o foobar.dat -B bar -t -o foobar.dat This will make two files. One with buba.dat that holds just the top instance and a foobar.dat file that has both foo and bar, but bar gets promoted to the top instance. Does that make sense? -- Steve
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