Date: Tue, 12 Dec 2017 12:49:28 -0800 (PST) From: "Rodney W. Grimes" <freebsd@pdx.rh.CN85.dnsmgr.net> To: Eugene Grosbein <eugen@grosbein.net> Cc: rgrimes@freebsd.org, Don Lewis <truckman@freebsd.org>, Alexey Dokuchaev <danfe@freebsd.org>, Konstantin Belousov <kostikbel@gmail.com>, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Conrad Meyer <cem@freebsd.org> Subject: Re: svn commit: r326758 - in head/sys/i386: conf include Message-ID: <201712122049.vBCKnSoE088417@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <5A302C50.4000709@grosbein.net>
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> On 13.12.2017 00:01, Rodney W. Grimes wrote:
>
> >> But many other parts of kernel think it's OK to allocate big arrays or
> >> structures on stack.
> >
> > We should probably start looking for those, something someone who is
> > offerring help but doesnt know what they might be good at, but can
> > read C code. They could be utililized t simply scan through the
> > code looking for this type of thing and bring it to the attention
> > of a area of expertise commiter.
>
> These can be found with simple script:
>
> cd /usr/src
> make TARGET_ARCH=i386 KERNCONF=GENERIC buildkernel
>
> cd /usr/obj/i386.i386/home/src/sys/GENERIC
> for o in *.o
> do
> objdump -d $o | awk -vn=$o '/sub .*,%esp/ {split ($NF,a,/[,$]/); printf "%u %s %s\n", a[2], a[2], n}'
> done | sort -rn > top.sub
>
> head -50 top.sub | while read d h o
> do
> objdump -d $o | fgrep -B7 "$h,%esp" | awk -vo=$o -vd=$d '/>:$/ {print d, o, $2}'
> done > top2.sub
>
> Here is what do we get in top2.sub:
>
> 4328 in6_proto.o <icmp6stat_sysctl>:
> 3312 in6_proto.o <ip6stat_sysctl>:
> 2232 sctp_pcb.o <sctp_load_addresses_from_init>:
...
Thank you Thank you THANK YOU! And imp has already removed one of these.
I wonder if fxing some of these sctp*.o would lead to the removal of the complaints
about that feature filling the stack.
> ...
>
> First column is total stack usage of kernel function (decimal),
> second is module name and third contains function name it question.
Can we get this put into a CI job?
Output anything that gets added to the list of things with a stack
usage greater than some N to an email sent. That way new violators
get flagged quickly and can be cleaned up by the commiter, then
slowly work down this list until things are stable again.
--
Rod Grimes rgrimes@freebsd.org
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