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From: Matthew Khouzam <matthew.khouzam-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
To: "lttng-dev-bnB2LGs2QVJ+nrgayQ7rhA@public.gmane.org"
	<lttng-dev-bnB2LGs2QVJ+nrgayQ7rhA@public.gmane.org>,
	Linux Tools developer discussions
	<linuxtools-dev-j9T/66MeVpFAfugRpC6u6w@public.gmane.org>
Subject: Tmf Ctf Parser Scalability issues (2/3)
Date: Tue, 26 Nov 2013 11:44:48 -0500	[thread overview]
Message-ID: <5294D000.60505@ericsson.com> (raw)

Hello all,
I was looking at the CTF parser in the TMF project of Linux Tools. I
have come up with three points where scalability will be an issue. I am
sending 3 emails, each one describing one of the issues so we can
aggregate them more cohesively. First a primer, CTF is a file format
that has traces written in packets, the packets are parts of files in
streams, the streams are files in a directory.

Issue 2: Packet size
CTF can have an packet with an unlimited size in within a stream. We use
a memory map to access the data. We are limited to 2GB as the size of an
individual packet, as far as I know. If a packet is larger this will
make the trace unreadable. I can imagine hardware tracers that have ~3gb
buffers and dump them to a file in a single packet would be affected by
this.

Proposed solution:
I envision fixing them by having a sliding window of the maximum memory
map size. I see a problem if a single event is say 3GB in size, but I
can't see a short term solution for that, would you have any suggestions
on this front?

             reply	other threads:[~2013-11-26 16:44 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-26 16:44 Matthew Khouzam [this message]
2013-11-26 23:05 ` Tmf Ctf Parser Scalability issues (2/3) Mathieu Desnoyers

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