Wireshark-dev: Re: [Wireshark-dev] memory allocation assertion failure reading 219MB file with
ronnie sahlberg wrote:
i think significant parts of the utilized memory is memory allocated by
wireshark itself for things like reassembly and state management of
protocols.
since most se allocation is done from within a dissector
once more/most of this is converted to use emem allocators we could
maybe do something like :
1, set an upper limit on how much memory we allow to be allocated by the
se allocator
2, when se_alloc is called and we have reached this limit, just cause
a new exception MemError
to cause dissection of the packet to be aborted but allow wireshark to
continue.
se_ allocations are per capture file, right? So wouldn't Wireshark also
have to stop dissecting further packets?
And what would the limit be? Sure I've only got 512 Mb RAM in my laptop
but I've got a server down the hall with 16 Gb RAM.
Have a preference? Have a bunch of #ifdef's for each platform to find
the [total or currently available] RAM?
On 8/25/06, *Jeff Morriss* <jeff.morriss@xxxxxxxxxxx
<mailto:jeff.morriss@xxxxxxxxxxx>> wrote:
Ravi Kondamuru wrote:
>
> Thanks for the wiki link.
>
> In the workarounds highlighed, I feel that point 3 (Split the
capture
> file into several smaller ones) can be made more appealing by
> programatically limiting the amount of data (packets/ memory
consumed/
> load time) wireshark already read/ used.
>
> Wireshark does something similar when a large file is selected in
the
> "Select a capture file" dialog box when opening a file. After 3 secs
> (prefs: file_open_preview_timeout) of reading a file, it stops
reading
> further and displays "more than xyz packets (preview timeout)".
>
> My point being, can the same approach be taken with large files
during
> the actual display?
>
> An option will let the user make wireshark parse the subsequent or
> previous packets till a timeout happens again. An option will let
users
> to make wireshark read the complete file before display. How much to
> read at a time can be determined as mentioned earlier on one of 1)
> number of packets read, 2) memory consumed so far or 3) amount of
time
> spent reading.
>
> Please mail, if you guys think of any issues that might make this
> approach not worth pursuing.
I think the problem with this approach is that it's difficult to know
[at least in a cross-platform manner that works on all the platforms
Wireshark runs on] when you're going to run out of memory until you
actually have run out of memory (and malloc() fails). As mentioned in
the Wiki, Wireshark and (more importantly as it's a bigger job to
change) some of the libraries Wireshark uses simply call abort() when
malloc() fails.
-J
> On 8/22/06, *Jeff Morriss* <jeff.morriss@xxxxxxxxxxx
<mailto:jeff.morriss@xxxxxxxxxxx>
> <mailto: jeff.morriss@xxxxxxxxxxx
<mailto:jeff.morriss@xxxxxxxxxxx>>> wrote:
>
>
>
> Guy Harris wrote:
> > Ravi Kondamuru wrote:
> >
> >> My question:
> >> Is there a known limit on the number of packets that
wireshark
> can deal
> >> with in a single file?
> >
> > The number of packets that Wireshark (or, I suspect, any
network
> > analyzer) can deal with is limited; due to a number of
factors,
> the GUI
> > widget used to implement the packet list display being one of
> them (it
> > allocates a string for the text value in every column,
which eats
> a lot
> > of memory), Wireshark's limit might be lower than some other
> analyzers.
> >
> > This is not a limit saying something such as "Wireshark can't
> read more
> > than 1,227,399 packets"; the point at which it'd run out
of memory
> > depends on the contents of the packets.
>
> See this page for more info:
>
> http://wiki.wireshark.org/KnownBugs/OutOfMemory
>
> _______________________________________________
> Wireshark-dev mailing list
> Wireshark-dev@xxxxxxxxxxxxx
<mailto:Wireshark-dev@xxxxxxxxxxxxx>
<mailto:Wireshark-dev@xxxxxxxxxxxxx
<mailto:Wireshark-dev@xxxxxxxxxxxxx>>
> http://www.wireshark.org/mailman/listinfo/wireshark-dev
> <http://www.wireshark.org/mailman/listinfo/wireshark-dev>
>
>
>
>
------------------------------------------------------------------------
>
> _______________________________________________
> Wireshark-dev mailing list
> Wireshark-dev@xxxxxxxxxxxxx <mailto:Wireshark-dev@xxxxxxxxxxxxx>
> http://www.wireshark.org/mailman/listinfo/wireshark-dev
_______________________________________________
Wireshark-dev mailing list
Wireshark-dev@xxxxxxxxxxxxx <mailto:Wireshark-dev@xxxxxxxxxxxxx>
http://www.wireshark.org/mailman/listinfo/wireshark-dev
------------------------------------------------------------------------
_______________________________________________
Wireshark-dev mailing list
Wireshark-dev@xxxxxxxxxxxxx
http://www.wireshark.org/mailman/listinfo/wireshark-dev
