This is why I need to run a persistent daemon rather than use CGI mode.
root@jy-cx:~# time perl -e exit
real 0m0.035s
user 0m0.000s
sys 0m0.030s
root@jy-cx:~# time perl -MMojolicious::Lite -e exit
real 0m11.011s
user 0m8.690s
sys 0m0.400s
root@jy-cx:~#
Looking at an strace there doesn't seem to be a single culprit for the
slow startup - there's just a lot of files to find, open, read, parse.
root@jy-cx:~# grep open ml.trace | wc -l
211
root@jy-cx:~#
...
root@jy-cx:~# grep open ml.trace | grep 12:21:26 | wc -l
16
root@jy-cx:~# grep open ml.trace | grep 12:21:27 | wc -l
28
root@jy-cx:~# grep open ml.trace | grep 12:21:28 | wc -l
16
root@jy-cx:~# grep open ml.trace | grep 12:21:29 | wc -l
19
root@jy-cx:~# grep open ml.trace | grep 12:21:30 | wc -l
13
root@jy-cx:~# grep open ml.trace | grep 12:21:31 | wc -l
2
root@jy-cx:~# grep open ml.trace | grep 12:21:32 | wc -l
15
root@jy-cx:~# grep open ml.trace | grep 12:21:33 | wc -l
8
root@jy-cx:~# grep open ml.trace | grep 12:21:34 | wc -l
18
root@jy-cx:~# grep open ml.trace | grep 12:21:35 | wc -l
24
root@jy-cx:~# grep open ml.trace | grep 12:21:36 | wc -l
8
root@jy-cx:~# grep open ml.trace | grep 12:21:37 | wc -l
19
root@jy-cx:~# grep open ml.trace | grep 12:21:38 | wc -l
11
root@jy-cx:~# grep open ml.trace | grep 12:21:39 | wc -l
14
root@jy-cx:~# grep open ml.trace | grep 12:21:40 | wc -l
0
root@jy-cx:~#
...
Initialising Time::HiRes::HiRes seems to be the single individual
parse/init step:
12:21:30.734184 open("/usr/lib/perl/5.22.0/Pod/Simple/BlackBox.pm",
O_RDONLY|O_L
ARGEFILE) = 16
12:21:31.607709 open("/usr/lib/perl/5.22.0/Time/HiRes.pm",
O_RDONLY|O_LARGEFILE) = 12
12:21:31.643254 open("/usr/lib/perl/5.22.0//auto/Time/HiRes/HiRes.so",
O_RDONLY|O_CLOEXEC) = 12
12:21:32.356811 open("/usr/lib/perl/vendor_perl/5.22.0/Mojo/Log.pm",
O_RDONLY|O_LARGEFILE) = 7
On Thu, 20 Sep 2018, Charlie Brady wrote:
>
> On Thu, 20 Sep 2018, Stefan Adams wrote:
>
> > Wow! That's fascinating! Thanks for sharing! I'm surprised by how
> > much the memory footprint grows for a minimal perl program to one
> > running M::L!
>
> Bear in mind this is one M::L program which has loaded (via the Mount
> plugin) a few dozen other M::L programs and then run for a few months
> (mostly idle).
>
> FWIW, this is on a PPC processor (perl 5.22.0, Mojolicious 7.33).
>
> > On Thu, Sep 20, 2018 at 2:57 PM Charlie Brady <
> > [email protected]> wrote:
> >
> > >
> > > Hi Stefan, thanks for trying to help.
> > >
> > > I know the perl executable will make some contribution to the memory
> > > footprint, but not much.
> > >
> > > I can measure that separately by running a minimum perl program and
> > > looking at its resource usage. If I run 'perl -e "<>"', I see this in
> > > /proc/$pid/status:
> > >
> > > ...
> > > VmPeak: 5476 kB
> > > VmSize: 5476 kB
> > > VmLck: 0 kB
> > > VmPin: 0 kB
> > > VmHWM: 3184 kB
> > > VmRSS: 3184 kB
> > > VmData: 468 kB
> > > VmStk: 132 kB
> > > VmExe: 4 kB
> > > VmLib: 4232 kB
> > > VmPTE: 24 kB
> > > VmPMD: 0 kB
> > > VmSwap: 0 kB
> > > Threads: 1
> > > ...
> > >
> > > The same data from my M::L daemon is:
> > >
> > > ...
> > > VmPeak: 135548 kB
> > > VmSize: 133540 kB
> > > VmLck: 0 kB
> > > VmPin: 0 kB
> > > VmHWM: 67016 kB
> > > VmRSS: 65988 kB
> > > VmData: 86940 kB
> > > VmStk: 176 kB
> > > VmExe: 4 kB
> > > VmLib: 31664 kB
> > > VmPTE: 132 kB
> > > VmPMD: 0 kB
> > > VmSwap: 0 kB
> > > Threads: 6
> > > ...
> > >
> > > CPAN has a few modules which might help gather some stats
> > > (Memory::Process, Memory::Stats, Memory::Usage). '-Dm' flag to perl might
> > > help too, if perl is compiled with DEBUG enabled.
> > >
> > > I notice that I can disable Mojolicious response cacheing; it'll be
> > > interesting to see what difference that makes.
> > >
> > > On Wed, 19 Sep 2018, Stefan Adams wrote:
> > >
> > > > I shouldn't involve myself in this topic because I haven't the
> > > > knowledge,
> > > > but it sounds fascinating. Wouldn't the majority of the 50MB memory
> > > > footprint be from the Perl interpreter itself? Wouldn't the question be,
> > > > how to reduce the size of the Perl interpreter? Different compile
> > > options?
> > > > e.g. I remember once compiling a "minimal" perl that was 2MB. I imagine
> > > > that would probably be insufficient to run Mojolicious, though I really
> > > > haven't a clue, but it suggests to me that it's possible to reduce the
> > > size
> > > > of the perl interpreter and, therefore it seems, the size of the
> > > > Mojolicious daemon?
> > > >
> > > > On Wed, Sep 19, 2018, 8:19 PM Charlie Brady <
> > > > [email protected]> wrote:
> > > >
> > > > >
> > > > > Some Mojolicious::Lite code I've written has been adapted by another
> > > group
> > > > > in my company to run on their embedded controller (limited CPU and
> > > limited
> > > > > memory). They are now asking for my advice on how to reduce the memory
> > > > > footprint of their daemon. It's consuming about 50MB at the moment.
> > > > >
> > > > > Does anyone have some advice on where to start looking at where memory
> > > is
> > > > > being used and how to minimise it?
> > > > >
> > > > > Thanks
> > > > >
> > > >
> > > >
> > >
> >
> >
>
