On Wed, Oct 27, 2021 at 7:58 PM Kalesh Singh <kaleshsingh@xxxxxxxxxx> wrote: > > On Wed, Oct 27, 2021 at 5:43 PM Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > > > > On Wed, 27 Oct 2021 19:54:54 -0400 > > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > > > On Wed, 27 Oct 2021 16:26:00 -0700 > > > Kalesh Singh <kaleshsingh@xxxxxxxxxx> wrote: > > > > > > > > Why don't you use 'tac'? I love that idea :) > > > > > Did you find any issue? > > > > > > > > Hi Masami, > > > > > > > > Thanks for the reviews. As with the first set of patches using tac > > > > gives a regression here, though I'm not sure why it doesn't work -- I > > > > also thought reversing the order would handle any dependencies > > > > correctly. > > > > > > Right, because are triggers not added by list_add_rcu() which adds to > > > the head of the list. > > > > Oops, so are the triggers shown in the reverse order? > > (newer entry is top, older one is bottom) > > Then do we need this patch, because we don't care about the > > dependency. > > In the case of the hist expression tests. they create a variable: > echo 'hist:keys=common_pid:x=1+2' >> trigger > > Then print its value in another histogram: > echo 'hist:keys=common_pid:vals=$x' >> trigger > > At least in this case, the triggers are listed from oldest (top) to > newest (bottom): > cat trigger > hist:keys=common_pid:vals=hitcount:x=3:sort=hitcount:size=2048 [active] I realized the result of the expression can be read directly from the trigger info, now that expressions of constants are squashed to a single constant. So we wouldn't need the second trigger to see the value and can drop this patch. I'll resend a new version. Thanks, Kalesh > hist:keys=common_pid:vals=hitcount,$x:sort=hitcount:size=2048 [active] > > So we need to remove the trigger with the var ref first. > > - Kalesh > > > > > If anything, shouldn't things be removed in order? > > > > Hmm, I think the trigger itself might better to be changed. If any dependency in > > the trigger list, it can not be restored from the copied file, like > > below may fail. > > > > cat events/foo/bar/trigger > /tmp/foo.bar.trigger > > cat /tmp/foo.bar.trigger > events/foo/bar/trigger > > > > (of course we can use 'tac' to restore it ...) > > > > This is > > > > Thank you, > > > > > > -- > > Masami Hiramatsu <mhiramat@xxxxxxxxxx>
