From: "Denis V. Lunev" <den@openvz.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 5/9] log: improve performance of qemu_log and qemu_log_mask if disabled
Date: Mon, 14 Mar 2016 18:07:06 +0300 [thread overview]
Message-ID: <56E6D39A.1020801@openvz.org> (raw)
In-Reply-To: <56E6CB13.3020406@redhat.com>
On 03/14/2016 05:30 PM, Paolo Bonzini wrote:
>
> On 14/03/2016 12:21, Denis V. Lunev wrote:
>> The patch is intended to avoid to perform any operation including
>> calculation of log function arguments when the log is not enabled due to
>> various reasons.
>>
>> Functions qemu_log and qemu_log_mask are replaced with variadic macros.
>>
>> Format checking performed by compiler will not suffer by this patch. It
>> will be done inside in fprintf arguments checking.
> Have you encountered a place that was calling them so hard that it
> caused performance problem? If so, the logging should probably be
> replaced by a tracepoint.
>
> Paolo
>
inline functions can have side-effects, i.e. the arguments of them
can be evaluated depending on the compiler. with this approach
we are sure that this will not happen, ever.
Den
next prev parent reply other threads:[~2016-03-14 15:23 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 11:21 [Qemu-devel] [PATCH v2 0/9] log: assorted improvements Denis V. Lunev
2016-03-14 11:21 ` [Qemu-devel] [PATCH 1/9] trace: do not always call exit() in trace_enable_events Denis V. Lunev
2016-03-14 14:25 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 2/9] qemu-log: fix cpu_reset log target Denis V. Lunev
2016-03-14 14:24 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 3/9] log: improve code in do_qemu_set_log Denis V. Lunev
2016-03-14 14:28 ` Paolo Bonzini
2016-03-16 11:20 ` Denis V. Lunev
2016-03-16 11:25 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 4/9] log: move qemu_log_close/qemu_log_flush from header to log.c Denis V. Lunev
2016-03-14 14:29 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 5/9] log: improve performance of qemu_log and qemu_log_mask if disabled Denis V. Lunev
2016-03-14 14:30 ` Paolo Bonzini
2016-03-14 15:07 ` Denis V. Lunev [this message]
2016-03-14 11:21 ` [Qemu-devel] [PATCH 6/9] log: log QMP commands and replies Denis V. Lunev
2016-03-14 14:33 ` Paolo Bonzini
2016-03-14 14:38 ` Daniel P. Berrange
2016-03-14 15:00 ` Denis V. Lunev
2016-03-14 15:05 ` Denis V. Lunev
2016-03-14 15:26 ` Daniel P. Berrange
2016-03-14 16:10 ` Denis V. Lunev
2016-03-14 16:37 ` Paolo Bonzini
2016-03-14 16:11 ` Daniel P. Berrange
2016-03-14 16:16 ` Denis V. Lunev
2016-03-14 16:40 ` Paolo Bonzini
2016-03-16 13:09 ` Denis V. Lunev
2016-03-16 13:11 ` Paolo Bonzini
2016-03-17 15:31 ` Daniel P. Berrange
2016-03-14 11:21 ` [Qemu-devel] [PATCH 7/9] log: report HMP command and event Denis V. Lunev
2016-03-14 14:36 ` Paolo Bonzini
2016-03-14 15:08 ` Denis V. Lunev
2016-03-14 16:35 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 8/9] log: report QAPI event Denis V. Lunev
2016-03-14 14:33 ` Paolo Bonzini
2016-03-14 11:21 ` [Qemu-devel] [PATCH 9/9] log: adds a timestamp to each log entry Denis V. Lunev
2016-03-14 14:39 ` Paolo Bonzini
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