From: Amit Shah <amit.shah@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
Alexander Graf <agraf@suse.de>
Subject: Re: [Qemu-devel] [PATCHv2] Fix virtio-console failure on unconnected pty
Date: Thu, 29 Dec 2011 20:26:02 +0530 [thread overview]
Message-ID: <20111229145602.GE4576@amit.redhat.com> (raw)
In-Reply-To: <4EFC79EE.6020000@de.ibm.com>
On (Thu) 29 Dec 2011 [15:32:14], Christian Borntraeger wrote:
> > port->throttled never becomes true for qemu.
>
> Huh? What did I miss below?
>
> if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) {
> virtio_serial_throttle_port(port, true);
'ret' here is the return value from info->have_data(), which is
hw/virtio-console.c:flush_buf(). That function returns the value that
qemu_chr_fe_write() returns, which is qemu-char.c:send_all() for pty,
tcp, unix sockets. send_all() just keeps spinning here if it can't
write, doesn't signal EAGAIN at all (or even a partial write).
Can you print out the return values of have_data to check what's going
on? Maybe you're hitting a case I never hit earlier and throttling
indeed does get enabled?
Amit
next prev parent reply other threads:[~2011-12-29 14:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-15 12:44 [Qemu-devel] [RFC] virtio-console fails on unconnected pty Christian Borntraeger
2011-12-16 9:23 ` Amit Shah
2011-12-29 12:47 ` [Qemu-devel] [PATCHv2] Fix virtio-console failure " Christian Borntraeger
2011-12-29 13:27 ` Amit Shah
2011-12-29 13:39 ` Andreas Färber
2011-12-29 14:04 ` Amit Shah
2011-12-29 14:16 ` Christian Borntraeger
2011-12-29 14:19 ` Christian Borntraeger
2011-12-29 14:26 ` Amit Shah
2011-12-29 14:32 ` Christian Borntraeger
2011-12-29 14:56 ` Amit Shah [this message]
2011-12-29 15:14 ` Christian Borntraeger
2011-12-29 15:14 ` Amit Shah
2012-01-02 15:34 ` Alexander Graf
2012-01-02 15:41 ` Christian Borntraeger
2012-01-02 16:55 ` Alexander Graf
2012-01-03 15:49 ` Amit Shah
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