From: Sergio Lopez <slp@redhat.com>
To: berrange@redhat.com, pbonzini@redhat.com,
marcandre.lureau@redhat.com, mst@redhat.com
Cc: qemu-devel@nongnu.org, Sergio Lopez <slp@redhat.com>
Subject: [Qemu-devel] [PATCH 0/3] Avoid retrying on serial_xmit with EPIPE
Date: Thu, 31 May 2018 09:45:58 +0200 [thread overview]
Message-ID: <20180531074601.10647-1-slp@redhat.com> (raw)
EPIPE is not a recoverable error, so retrying on serial_xmit is a waste of CPU
cycles, and can potentially comprosie the Guest OS stability if both the vCPU
and the emulator thread are pinned to the same pCPU, with the first one
actively polling the serial device and barely giving time to the second to make
any actual progress.
Sergio Lopez (3):
io: Implement QIO_CHANNEL_ERR_BROKEN
chardev: On QIO_CHANNEL_ERR_BROKEN set errno to EPIPE
hw/char/serial: Don't retry on serial_xmit if errno == EPIPE
chardev/char-io.c | 3 +++
hw/char/serial.c | 1 +
include/io/channel.h | 1 +
io/channel-file.c | 3 +++
4 files changed, 8 insertions(+)
--
1.8.3.1
next reply other threads:[~2018-05-31 7:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-31 7:45 Sergio Lopez [this message]
2018-05-31 7:45 ` [Qemu-devel] [PATCH 1/3] io: Implement QIO_CHANNEL_ERR_BROKEN Sergio Lopez
2018-06-01 11:50 ` Daniel P. Berrangé
2018-05-31 7:46 ` [Qemu-devel] [PATCH 2/3] chardev: On QIO_CHANNEL_ERR_BROKEN set errno to EPIPE Sergio Lopez
2018-05-31 9:48 ` Marc-André Lureau
2018-05-31 11:03 ` Sergio Lopez
2018-06-01 11:51 ` Daniel P. Berrangé
2018-05-31 7:46 ` [Qemu-devel] [PATCH 3/3] hw/char/serial: Don't retry on serial_xmit if errno == EPIPE Sergio Lopez
2018-05-31 9:52 ` Marc-André Lureau
2018-05-31 11:03 ` Sergio Lopez
2018-05-31 11:07 ` Marc-André Lureau
2018-06-01 11:52 ` Daniel P. Berrangé
2018-06-01 12:05 ` Sergio Lopez
2018-06-01 12:16 ` Paolo Bonzini
2018-06-01 12:28 ` Sergio Lopez
2018-06-01 12:31 ` Paolo Bonzini
2018-06-01 12:43 ` Peter Maydell
2018-06-01 16:20 ` Sergio Lopez
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