From: David Howells <dhowells@redhat.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: dhowells@redhat.com, David Ahern <dsahern@gmail.com>,
netdev@vger.kernel.org, linux-afs@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next] udp: Add tracepoints to monitor skbs going in and out of a UDP socket
Date: Fri, 05 Oct 2018 07:46:50 +0100 [thread overview]
Message-ID: <9724.1538722010@warthog.procyon.org.uk> (raw)
In-Reply-To: <20181005020316.7cqlcfkedhamwhtt@ast-mbp.dhcp.thefacebook.com>
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> - kprobes at the top of the function don't use traps and they've been
> optimized over the years to have very low overhead
To quote kprobes.txt:
How Does a Kprobe Work?
-----------------------
When a kprobe is registered, Kprobes makes a copy of the probed
instruction and replaces the first byte(s) of the probed instruction
with a breakpoint instruction (e.g., int3 on i386 and x86_64).
Perhaps the docs need updating.
However, for my purposes, tracepoints are easier.
Anyway, as I said, I don't feel that strongly about the patch. It was useful
for me, and I thought it might be useful for other people.
David
prev parent reply other threads:[~2018-10-05 6:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-04 8:30 [PATCH net-next] udp: Add tracepoints to monitor skbs going in and out of a UDP socket David Howells
2018-10-04 16:36 ` David Ahern
2018-10-04 16:54 ` David Howells
2018-10-04 17:19 ` Alexei Starovoitov
2018-10-04 23:24 ` David Howells
2018-10-05 2:03 ` Alexei Starovoitov
2018-10-05 6:46 ` David Howells [this message]
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