Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg wrote: > On 11/12/13 11:40 PM, Ingo Molnar wrote: > >So if you prefer unit-less lines that's defensible, perhaps output the > >unit somewhere else: > > > > syscallcalls min avg max stddev > >(msec) (msec) (msec)(%) > > --- -- > > sendmsg20.0020.0050.008 55.00 > > recvmsg20.0020.0030.005 44.00 > > epoll_wait 10.0000.0000.000 0.00 > > > >or so? > > Looks good. I'll make a patch later today unless someone else beats > me to it. Maybe this variant is even better: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.0% recvmsg20.0020.0030.005 44.0% epoll_wait 10.0000.0000.000 0.0% Note how we can squeeze the % into that column by using only single digit precision percentage - double digit is pretty pointless IMO. Also note that the different nature of the stddev column stands out better if there's four more horizontal spaces separating it from the other colums. But maybe it's just me. Btw., the msec colums seem a bit narrow, they allow up to .999msec values which is 10 seconds. If any delay is larger than that then what happens, do the values get unaligned in an ugly fashion like they so often do in 'vmstat'? Maybe space for one or two digits more would give it more breathing space: syscallcalls min avg max stddev (msec)(msec)(msec)(%) --- - - - -- sendmsg2 0.002 0.005 0.008 55.0% recvmsg2 0.002 0.003 0.005 44.0% epoll_wait 1 0.000 0.000 0.000 0.0% This still looks directly pasteable into email and commit logs and looks nicely compact on my terminals as well. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg penb...@iki.fi wrote: On 11/12/13 11:40 PM, Ingo Molnar wrote: So if you prefer unit-less lines that's defensible, perhaps output the unit somewhere else: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 or so? Looks good. I'll make a patch later today unless someone else beats me to it. Maybe this variant is even better: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.0% recvmsg20.0020.0030.005 44.0% epoll_wait 10.0000.0000.000 0.0% Note how we can squeeze the % into that column by using only single digit precision percentage - double digit is pretty pointless IMO. Also note that the different nature of the stddev column stands out better if there's four more horizontal spaces separating it from the other colums. But maybe it's just me. Btw., the msec colums seem a bit narrow, they allow up to .999msec values which is 10 seconds. If any delay is larger than that then what happens, do the values get unaligned in an ugly fashion like they so often do in 'vmstat'? Maybe space for one or two digits more would give it more breathing space: syscallcalls min avg max stddev (msec)(msec)(msec)(%) --- - - - -- sendmsg2 0.002 0.005 0.008 55.0% recvmsg2 0.002 0.003 0.005 44.0% epoll_wait 1 0.000 0.000 0.000 0.0% This still looks directly pasteable into email and commit logs and looks nicely compact on my terminals as well. Thanks, Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13 11:40 PM, Ingo Molnar wrote: So if you prefer unit-less lines that's defensible, perhaps output the unit somewhere else: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 or so? Looks good. I'll make a patch later today unless someone else beats me to it. Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg wrote: > > %. That was dropped in the recent output change. > > Sorry about that. Why do we show them in percentages, btw? Standard > deviation is usually represented in the same unit as the data to make it > readable. So, the problem with output in the same unit is that it's hard to tell 'at a glance' what the real, relative stddev is: syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 0.001 recvmsg20.0020.0030.005 0.0003 epoll_wait 10.0000.0000.000 0.000 it's also harder to compare stddevs side by side if they are absolute. The way we try to solve this in perf stat is to output: comet:~/tip> perf stat -a --repeat 10 --null usleep 1000 Performance counter stats for 'system wide' (10 runs): 0.001772475 seconds time elapsed ( +- 0.58% ) Oh, btw., would anyone would like to implement a cool new 'perf time' subcommand, which offers time(1) look-alike output but with better precision and sttdev output? comet:~> time usleep 1000 real0m0.002s user0m0.000s sys 0m0.000s # Mockup: comet:~> perf time --repeat 10 usleep 1000 real0m0.002s [ +- 1.38% ] user0m0.000s [ +- 0.53% ] sys 0m0.000s [ +- 0.43% ] ? I'd use it instead of 'time' all the time ;-) Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13, 2:38 PM, Pekka Enberg wrote: Sorry about that. Why do we show them in percentages, btw? Standard deviation is usually represented in the same unit as the data to make it readable. Consistency. perf-stat shows relative stddev, for example. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* David Ahern wrote: > On 11/12/13, 2:33 PM, Ingo Molnar wrote: > >>> Summary of events: > >>> > >>> dbus-daemon (555), 10 events, 0.0%, 0.000 msec > >>> > >>> msec/call > >>>syscallcalls min avg max stddev > >>>--- -- > >>>sendmsg20.0020.0050.008 55.00 > >>>recvmsg20.0020.0030.005 44.00 > >>>epoll_wait 10.0000.0000.000 0.00 > >In what units is stddev? Percentage? If yes then it might be useful to > >output it as %. [and probably to restrict precision to a single digit, > >standard deviations are rarely more accurate than 0.1%.] > > > > %. That was dropped in the recent output change. So if you prefer unit-less lines that's defensible, perhaps output the unit somewhere else: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 or so? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13 11:36 PM, David Ahern wrote: On 11/12/13, 2:33 PM, Ingo Molnar wrote: > Summary of events: > > dbus-daemon (555), 10 events, 0.0%, 0.000 msec > > msec/call >syscallcalls min avg max stddev >--- -- >sendmsg20.0020.0050.008 55.00 >recvmsg20.0020.0030.005 44.00 >epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] %. That was dropped in the recent output change. Sorry about that. Why do we show them in percentages, btw? Standard deviation is usually represented in the same unit as the data to make it readable. Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13, 2:33 PM, Ingo Molnar wrote: > Summary of events: > > dbus-daemon (555), 10 events, 0.0%, 0.000 msec > > msec/call >syscallcalls min avg max stddev >--- -- >sendmsg20.0020.0050.008 55.00 >recvmsg20.0020.0030.005 44.00 >epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] %. That was dropped in the recent output change. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg wrote: > The output of 'perf trace --summary' tries to be too cute with > formatting and makes it very hard to read. Simplify it in the spirit of > "strace -c": > > [penberg@localhost libtrading]$ perf trace -a --duration 1 --summary -- > sleep 1 > ^C Btw., just a very small feature suggestion - instead of forcing the somewhat counter-intuitive '-- sleep X' pattern it might be helpful to have a general option parser for 'delay' values, which would allow a wide range of time units like: --delay 10.5h --delay 0.1s --delay 0.1sec etc. - with the default unit being 'seconds'. That parser could then be applied to '--duration' filter as well, allowing things like: --duration 10sec which IMHO are more obvious to read (and easier to remember!) than '--duration 1'. > Summary of events: > > dbus-daemon (555), 10 events, 0.0%, 0.000 msec > > msec/call >syscallcalls min avg max stddev >--- -- >sendmsg20.0020.0050.008 55.00 >recvmsg20.0020.0030.005 44.00 >epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] > NetworkManager (667), 56 events, 0.0%, 0.000 msec > > msec/call >syscallcalls min avg max stddev >--- -- >poll 20.0000.0020.003 100.00 >sendmsg 100.0040.0070.016 15.41 >recvmsg 160.0020.0030.005 8.24 > > zfs-fuse (669), 4 events, 0.0%, 0.000 msec > > msec/call >syscallcalls min avg max stddev >--- -- >futex 20.0000.0010.002 100.00 Nice looking output btw! :-) Acked-by: Ingo Molnar Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg penb...@kernel.org wrote: The output of 'perf trace --summary' tries to be too cute with formatting and makes it very hard to read. Simplify it in the spirit of strace -c: [penberg@localhost libtrading]$ perf trace -a --duration 1 --summary -- sleep 1 ^C Btw., just a very small feature suggestion - instead of forcing the somewhat counter-intuitive '-- sleep X' pattern it might be helpful to have a general option parser for 'delay' values, which would allow a wide range of time units like: --delay 10.5h --delay 0.1s --delay 0.1sec etc. - with the default unit being 'seconds'. That parser could then be applied to '--duration' filter as well, allowing things like: --duration 10sec which IMHO are more obvious to read (and easier to remember!) than '--duration 1'. Summary of events: dbus-daemon (555), 10 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] NetworkManager (667), 56 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- poll 20.0000.0020.003 100.00 sendmsg 100.0040.0070.016 15.41 recvmsg 160.0020.0030.005 8.24 zfs-fuse (669), 4 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- futex 20.0000.0010.002 100.00 Nice looking output btw! :-) Acked-by: Ingo Molnar mi...@kernel.org Thanks, Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13, 2:33 PM, Ingo Molnar wrote: Summary of events: dbus-daemon (555), 10 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] %. That was dropped in the recent output change. David -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13 11:36 PM, David Ahern wrote: On 11/12/13, 2:33 PM, Ingo Molnar wrote: Summary of events: dbus-daemon (555), 10 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] %. That was dropped in the recent output change. Sorry about that. Why do we show them in percentages, btw? Standard deviation is usually represented in the same unit as the data to make it readable. Pekka -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* David Ahern dsah...@gmail.com wrote: On 11/12/13, 2:33 PM, Ingo Molnar wrote: Summary of events: dbus-daemon (555), 10 events, 0.0%, 0.000 msec msec/call syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 In what units is stddev? Percentage? If yes then it might be useful to output it as %. [and probably to restrict precision to a single digit, standard deviations are rarely more accurate than 0.1%.] %. That was dropped in the recent output change. So if you prefer unit-less lines that's defensible, perhaps output the unit somewhere else: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 or so? Thanks, Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13, 2:38 PM, Pekka Enberg wrote: Sorry about that. Why do we show them in percentages, btw? Standard deviation is usually represented in the same unit as the data to make it readable. Consistency. perf-stat shows relative stddev, for example. David -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
* Pekka Enberg penb...@iki.fi wrote: %. That was dropped in the recent output change. Sorry about that. Why do we show them in percentages, btw? Standard deviation is usually represented in the same unit as the data to make it readable. So, the problem with output in the same unit is that it's hard to tell 'at a glance' what the real, relative stddev is: syscallcalls min avg max stddev --- -- sendmsg20.0020.0050.008 0.001 recvmsg20.0020.0030.005 0.0003 epoll_wait 10.0000.0000.000 0.000 it's also harder to compare stddevs side by side if they are absolute. The way we try to solve this in perf stat is to output: comet:~/tip perf stat -a --repeat 10 --null usleep 1000 Performance counter stats for 'system wide' (10 runs): 0.001772475 seconds time elapsed ( +- 0.58% ) Oh, btw., would anyone would like to implement a cool new 'perf time' subcommand, which offers time(1) look-alike output but with better precision and sttdev output? comet:~ time usleep 1000 real0m0.002s user0m0.000s sys 0m0.000s # Mockup: comet:~ perf time --repeat 10 usleep 1000 real0m0.002s [ +- 1.38% ] user0m0.000s [ +- 0.53% ] sys 0m0.000s [ +- 0.43% ] ? I'd use it instead of 'time' all the time ;-) Thanks, Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] perf trace: Simplify '--summary' output
On 11/12/13 11:40 PM, Ingo Molnar wrote: So if you prefer unit-less lines that's defensible, perhaps output the unit somewhere else: syscallcalls min avg max stddev (msec) (msec) (msec)(%) --- -- sendmsg20.0020.0050.008 55.00 recvmsg20.0020.0030.005 44.00 epoll_wait 10.0000.0000.000 0.00 or so? Looks good. I'll make a patch later today unless someone else beats me to it. Pekka -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
