From: Bob Chen <a175818323@gmail.com>
To: qemu-block@nongnu.org, qemu-devel@nongnu.org
Subject: [Qemu-devel] QEMU 1.1.2: block IO throttle might occasionally freeze running process's IO to zero
Date: Thu, 1 Dec 2016 12:07:03 +0800 [thread overview]
Message-ID: <CAMxP3BQptSjDJCoakSjT4CU-034rj4hgQ5JoQsoxMCk-3sQpKw@mail.gmail.com> (raw)
Test case:
1. QEMU 1.1.2
2. Run fio inside the vm, give it some pressure. Watch the realtime
throughput
3. block_set_io_throttle drive_2 100000000 0 0 2000 0 0 # throttle
bps and iops, any value
4. Observed that the IO is very likely to freeze to zero. The fio process
stuck!
5. Kill the former fio process, start a new one. The IO turns back to normal
Didn't reproduce it with QEMU 2.5.
Actually I'm not wishfully thinking the community would help fix this bug
on such an ancient version. Just hope someone can tell me what is the root
cause. Then I have to evaluate whether I should move to higher version
QEMU, or fix this bug on 1.1.2 in-place(if it is a small one).
next reply other threads:[~2016-12-01 4:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-01 4:07 Bob Chen [this message]
2016-12-01 9:52 ` [Qemu-devel] QEMU 1.1.2: block IO throttle might occasionally freeze running process's IO to zero Fam Zheng
2016-12-01 10:16 ` Paolo Bonzini
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=CAMxP3BQptSjDJCoakSjT4CU-034rj4hgQ5JoQsoxMCk-3sQpKw@mail.gmail.com \
--to=a175818323@gmail.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.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 NNTP newsgroup(s).