From: Markus Armbruster <armbru@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org,
"Hanna Reitz" <hreitz@redhat.com>,
"Kevin Wolf" <kwolf@redhat.com>,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Christian Schoenebeck" <qemu_oss@crudebyte.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Manos Pitsidianakis" <manos.pitsidianakis@linaro.org>,
"Stefan Weil" <sw@weilnetz.de>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Dr. David Alan Gilbert" <dave@treblig.org>
Subject: Re: [PATCH v3 08/20] log: avoid repeated prefix on incremental qemu_log calls
Date: Wed, 24 Sep 2025 14:34:30 +0200 [thread overview]
Message-ID: <87ecrw112h.fsf@pond.sub.org> (raw)
In-Reply-To: <87h5ws5nxs.fsf@pond.sub.org> (Markus Armbruster's message of "Wed, 24 Sep 2025 09:06:55 +0200")
Pondering the interleave between logging and error reporting led me to
an interleave between error reporting and itself.
vreport() prints a single line to stderr in several parts:
* Timestamp (if enabled)
* Guest name (if enabled)
* Program name
* Location (if there is one)
* Message type
* Message text
* Newline
Stdio guarantees that each part comes out as a whole even when other
threads print to the same FILE at the same time. But another thread's
print output can still squeeze in between parts. Unlikely, but
possible. To avoid it, we'd need to guard vreport()'s printing with
flockfile() ... funlockfile().
Thoughts?
next prev parent reply other threads:[~2025-09-24 12:36 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-10 18:03 [PATCH v3 00/20] util: sync error_report & qemu_log output more closely Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 01/20] include: define constant for early constructor priority Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 02/20] monitor: initialize global data from a constructor Daniel P. Berrangé
2025-09-17 14:07 ` Markus Armbruster
2025-09-17 15:31 ` Daniel P. Berrangé
2025-09-18 6:30 ` Markus Armbruster
2025-09-10 18:03 ` [PATCH v3 03/20] system: unconditionally enable thread naming Daniel P. Berrangé
2025-09-11 12:18 ` Ján Tomko
2025-09-19 8:20 ` Markus Armbruster
2025-09-19 13:32 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 04/20] util: expose qemu_thread_set_name Daniel P. Berrangé
2025-09-19 8:39 ` Markus Armbruster
2025-09-24 8:37 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 05/20] audio: make jackaudio use qemu_thread_set_name Daniel P. Berrangé
2025-09-11 13:21 ` Christian Schoenebeck
2025-09-12 14:58 ` Daniel P. Berrangé
2025-09-19 8:46 ` Markus Armbruster
2025-09-10 18:03 ` [PATCH v3 06/20] util: set the name for the 'main' thread Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 07/20] util: add API to fetch the current thread name Daniel P. Berrangé
2025-09-19 8:59 ` Markus Armbruster
2025-09-19 9:05 ` Daniel P. Berrangé
2025-09-19 11:35 ` Markus Armbruster
2025-09-23 12:12 ` Markus Armbruster
2025-09-24 8:55 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 08/20] log: avoid repeated prefix on incremental qemu_log calls Daniel P. Berrangé
2025-09-10 23:20 ` Dr. David Alan Gilbert
2025-09-11 8:49 ` Richard Henderson
2025-09-17 14:11 ` Markus Armbruster
2025-09-17 15:33 ` Daniel P. Berrangé
2025-09-23 12:46 ` Philippe Mathieu-Daudé
2025-09-23 14:28 ` Markus Armbruster
2025-09-23 14:55 ` Daniel P. Berrangé
2025-09-24 7:06 ` Markus Armbruster
2025-09-24 7:12 ` Daniel P. Berrangé
2025-09-24 9:20 ` Daniel P. Berrangé
2025-09-24 12:34 ` Markus Armbruster [this message]
2025-09-24 13:30 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 09/20] ui/vnc: remove use of error_printf_unless_qmp() Daniel P. Berrangé
2025-09-11 0:08 ` Dr. David Alan Gilbert
2025-09-11 8:51 ` Richard Henderson
2025-09-11 17:54 ` Richard Henderson
2025-09-12 15:11 ` Daniel P. Berrangé
2025-09-19 11:42 ` Markus Armbruster
2025-09-10 18:03 ` [PATCH v3 10/20] monitor: remove redundant error_[v]printf_unless_qmp Daniel P. Berrangé
2025-09-11 8:50 ` Richard Henderson
2025-09-19 11:42 ` Markus Armbruster
2025-09-23 12:48 ` Philippe Mathieu-Daudé
2025-09-10 18:03 ` [PATCH v3 11/20] monitor: move error_vprintf() back to error-report.c Daniel P. Berrangé
2025-09-11 8:55 ` Richard Henderson
2025-09-19 12:27 ` Markus Armbruster
2025-09-19 13:43 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 12/20] monitor: introduce monitor_cur_hmp() function Daniel P. Berrangé
2025-09-11 17:52 ` Richard Henderson
2025-09-19 12:43 ` Markus Armbruster
2025-09-19 13:29 ` Daniel P. Berrangé
2025-09-20 7:06 ` Markus Armbruster
2025-09-20 11:54 ` Dr. David Alan Gilbert
2025-09-22 8:38 ` Markus Armbruster
2025-09-24 16:09 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 13/20] util: don't skip error prefixes when QMP is active Daniel P. Berrangé
2025-09-22 8:43 ` Markus Armbruster
2025-09-10 18:03 ` [PATCH v3 14/20] util: fix interleaving of error & trace output Daniel P. Berrangé
2025-09-11 18:01 ` Richard Henderson
2025-09-11 18:05 ` Richard Henderson
2025-09-12 16:30 ` Daniel P. Berrangé
2025-09-22 12:16 ` Markus Armbruster
2025-09-10 18:03 ` [PATCH v3 15/20] util: introduce common helper for error-report & log code Daniel P. Berrangé
2025-09-11 18:02 ` Richard Henderson
2025-09-10 18:03 ` [PATCH v3 16/20] util: convert error-report & log to message API for timestamp Daniel P. Berrangé
2025-09-11 18:04 ` Richard Henderson
2025-09-10 18:03 ` [PATCH v3 17/20] util: add support for formatting a workload name in messages Daniel P. Berrangé
2025-09-11 18:06 ` Richard Henderson
2025-09-11 20:27 ` Dr. David Alan Gilbert
2025-09-12 8:34 ` Daniel P. Berrangé
2025-09-12 11:18 ` Dr. David Alan Gilbert
2025-09-10 18:03 ` [PATCH v3 18/20] util: add support for formatting a program " Daniel P. Berrangé
2025-09-11 18:07 ` Richard Henderson
2025-09-11 18:08 ` Richard Henderson
2025-09-12 16:33 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 19/20] util: add support for formatting thread info " Daniel P. Berrangé
2025-09-11 18:11 ` Richard Henderson
2025-09-12 8:36 ` Daniel P. Berrangé
2025-09-10 18:03 ` [PATCH v3 20/20] util: add brackets around guest name in message context Daniel P. Berrangé
2025-09-11 18:12 ` Richard Henderson
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