From: Yun-Chih Chen <b03902074@ntu.edu.tw>
To: David Smith <dsmith@redhat.com>
Cc: systemtap@sourceware.org
Subject: Re: Read fault when running example network/nfsd-trace.stp stap
Date: Tue, 30 May 2017 22:35:00 -0000 [thread overview]
Message-ID: <CANeCTtQnLSWL9-Pq_hSzz2cf8W2YZhr1GRra2qc+jqq1COYVVw@mail.gmail.com> (raw)
In-Reply-To: <0574e90c6ac44b1e8f4fb44029b69e7f@EXCHCAS07.ntu.internal>
On Wed, May 31, 2017 at 2:44 AM, David Smith <dsmith@redhat.com> wrote:
> Hmm. The good news here is that systemtap is properly exiting here
> instead of accessing that NULL pointer and crashing your system.
>
> Does this work for a while then fail or does it always fail on the
> first read request?
It always fail at the first NFSv3 read request (NFSv4 is okay).
To speed up the tracing, I ended up printing inode number only and get
filename from inode number at post-processing stage:
probe kernel.function("nfsd_vfs_read@fs/nfsd/vfs.c") !,
module("nfsd").function("nfsd_vfs_read@fs/nfsd/vfs.c") ? {
i = $file->f_inode;
inode = @cast(i, "struct inode")->i_ino;
printf("N %d %d %d\n", gettimeofday_ms(), inode);
}
next prev parent reply other threads:[~2017-05-30 22:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-26 14:59 Yun-Chih Chen
2017-05-27 19:34 ` Daniel Doron
2017-05-30 18:44 ` David Smith
[not found] ` <0574e90c6ac44b1e8f4fb44029b69e7f@EXCHCAS07.ntu.internal>
2017-05-30 22:35 ` Yun-Chih Chen [this message]
2017-05-30 23:01 ` Frank Ch. Eigler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CANeCTtQnLSWL9-Pq_hSzz2cf8W2YZhr1GRra2qc+jqq1COYVVw@mail.gmail.com \
--to=b03902074@ntu.edu.tw \
--cc=dsmith@redhat.com \
--cc=systemtap@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).