* [PATCH v2 1/4] meson: Explicit TCG backend used
2021-01-22 10:58 [PATCH v2 0/4] meson: Try to clarify TCG / TCI options for new users Philippe Mathieu-Daudé
@ 2021-01-22 10:58 ` Philippe Mathieu-Daudé
2021-01-22 10:58 ` [PATCH v2 2/4] meson: Warn when TCI is selected but TCG backend is available Philippe Mathieu-Daudé
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-01-22 10:58 UTC (permalink / raw)
To: qemu-devel
Cc: Thomas Huth, Daniel P . Berrange, Stefan Weil, Richard Henderson,
Paolo Bonzini, Philippe Mathieu-Daudé
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
meson.build | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/meson.build b/meson.build
index 8535a83fb70..d5b76150e49 100644
--- a/meson.build
+++ b/meson.build
@@ -229,7 +229,7 @@
if not get_option('tcg').disabled()
if cpu not in supported_cpus
if 'CONFIG_TCG_INTERPRETER' in config_host
- warning('Unsupported CPU @0@, will use TCG with TCI (experimental)'.format(cpu))
+ warning('Unsupported CPU @0@, will use TCG with TCI (experimental and slow)'.format(cpu))
else
error('Unsupported CPU @0@, try --enable-tcg-interpreter'.format(cpu))
endif
@@ -2419,8 +2419,12 @@
endif
summary_info += {'TCG support': config_all.has_key('CONFIG_TCG')}
if config_all.has_key('CONFIG_TCG')
+ if config_host.has_key('CONFIG_TCG_INTERPRETER')
+ summary_info += {'TCG backend': 'TCG interpreter (experimental)'}
+ else
+ summary_info += {'TCG backend': 'native (@0@)'.format(cpu)}
+ endif
summary_info += {'TCG debug enabled': config_host.has_key('CONFIG_DEBUG_TCG')}
- summary_info += {'TCG interpreter': config_host.has_key('CONFIG_TCG_INTERPRETER')}
endif
summary_info += {'target list': ' '.join(target_dirs)}
if have_system
--
2.26.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/4] meson: Warn when TCI is selected but TCG backend is available
2021-01-22 10:58 [PATCH v2 0/4] meson: Try to clarify TCG / TCI options for new users Philippe Mathieu-Daudé
2021-01-22 10:58 ` [PATCH v2 1/4] meson: Explicit TCG backend used Philippe Mathieu-Daudé
@ 2021-01-22 10:58 ` Philippe Mathieu-Daudé
2021-01-22 10:58 ` [PATCH v2 3/4] configure: Improve TCI feature description Philippe Mathieu-Daudé
2021-01-22 10:58 ` [RFC PATCH v2 4/4] configure: Reword --enable-tcg-interpreter as --disable-native-tcg Philippe Mathieu-Daudé
3 siblings, 0 replies; 7+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-01-22 10:58 UTC (permalink / raw)
To: qemu-devel
Cc: Thomas Huth, Daniel P . Berrange, Stefan Weil, Richard Henderson,
Paolo Bonzini, Philippe Mathieu-Daudé
Some new users get confused with 'TCG' and 'TCI', and enable TCI
support expecting to enable TCG.
Emit a warning when native TCG backend is available on the
host architecture, mentioning this is a suboptimal configuration.
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
meson.build | 3 +++
1 file changed, 3 insertions(+)
diff --git a/meson.build b/meson.build
index d5b76150e49..d3df5fa3516 100644
--- a/meson.build
+++ b/meson.build
@@ -234,6 +234,9 @@
error('Unsupported CPU @0@, try --enable-tcg-interpreter'.format(cpu))
endif
endif
+ if 'CONFIG_TCG_INTERPRETER' in config_host and cpu in supported_cpus
+ warning('Experimental TCI requested while native TCG is available on @0@, suboptimal performance expected'.format(cpu))
+ endif
accelerators += 'CONFIG_TCG'
config_host += { 'CONFIG_TCG': 'y' }
endif
--
2.26.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 3/4] configure: Improve TCI feature description
2021-01-22 10:58 [PATCH v2 0/4] meson: Try to clarify TCG / TCI options for new users Philippe Mathieu-Daudé
2021-01-22 10:58 ` [PATCH v2 1/4] meson: Explicit TCG backend used Philippe Mathieu-Daudé
2021-01-22 10:58 ` [PATCH v2 2/4] meson: Warn when TCI is selected but TCG backend is available Philippe Mathieu-Daudé
@ 2021-01-22 10:58 ` Philippe Mathieu-Daudé
2021-01-22 11:32 ` Thomas Huth
2021-01-22 10:58 ` [RFC PATCH v2 4/4] configure: Reword --enable-tcg-interpreter as --disable-native-tcg Philippe Mathieu-Daudé
3 siblings, 1 reply; 7+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-01-22 10:58 UTC (permalink / raw)
To: qemu-devel
Cc: Thomas Huth, Daniel P . Berrange, Stefan Weil, Richard Henderson,
Paolo Bonzini, Philippe Mathieu-Daudé
Users might want to enable all features, without realizing some
features have negative effect. Mention the TCI feature is slow
and experimental, hoping it will be selected knowingly.
Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
configure | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/configure b/configure
index 9f016b06b54..71bdc523aa0 100755
--- a/configure
+++ b/configure
@@ -1753,7 +1753,7 @@ Advanced options (experts only):
--with-trace-file=NAME Full PATH,NAME of file to store traces
Default:trace-<pid>
--disable-slirp disable SLIRP userspace network connectivity
- --enable-tcg-interpreter enable TCG with bytecode interpreter (TCI)
+ --enable-tcg-interpreter enable TCG with bytecode interpreter (experimental and slow)
--enable-malloc-trim enable libc malloc_trim() for memory optimization
--oss-lib path to OSS library
--cpu=CPU Build for host CPU [$cpu]
--
2.26.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 3/4] configure: Improve TCI feature description
2021-01-22 10:58 ` [PATCH v2 3/4] configure: Improve TCI feature description Philippe Mathieu-Daudé
@ 2021-01-22 11:32 ` Thomas Huth
0 siblings, 0 replies; 7+ messages in thread
From: Thomas Huth @ 2021-01-22 11:32 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Paolo Bonzini, Richard Henderson, Daniel P . Berrange, Stefan Weil
On 22/01/2021 11.58, Philippe Mathieu-Daudé wrote:
> Users might want to enable all features, without realizing some
> features have negative effect. Mention the TCI feature is slow
> and experimental, hoping it will be selected knowingly.
>
> Suggested-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> configure | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index 9f016b06b54..71bdc523aa0 100755
> --- a/configure
> +++ b/configure
> @@ -1753,7 +1753,7 @@ Advanced options (experts only):
> --with-trace-file=NAME Full PATH,NAME of file to store traces
> Default:trace-<pid>
> --disable-slirp disable SLIRP userspace network connectivity
> - --enable-tcg-interpreter enable TCG with bytecode interpreter (TCI)
> + --enable-tcg-interpreter enable TCG with bytecode interpreter (experimental and slow)
I'd prefer if we could keep the "TCI" in there ... I remember having grep'ed
for "tci" in the help output in the past, so I think it would be good to
keep the TLA here. Maybe just put "TCI, slow" in the parantheses and omit
"experimental"?
Thomas
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC PATCH v2 4/4] configure: Reword --enable-tcg-interpreter as --disable-native-tcg
2021-01-22 10:58 [PATCH v2 0/4] meson: Try to clarify TCG / TCI options for new users Philippe Mathieu-Daudé
` (2 preceding siblings ...)
2021-01-22 10:58 ` [PATCH v2 3/4] configure: Improve TCI feature description Philippe Mathieu-Daudé
@ 2021-01-22 10:58 ` Philippe Mathieu-Daudé
2021-01-22 11:33 ` Thomas Huth
3 siblings, 1 reply; 7+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-01-22 10:58 UTC (permalink / raw)
To: qemu-devel
Cc: Thomas Huth, Daniel P . Berrange, Stefan Weil, Richard Henderson,
Paolo Bonzini, Philippe Mathieu-Daudé
Users might want to enable all features, without realizing some
features have negative effect. Rename '--enable-tcg-interpreter'
as '--disable-native-tcg' to avoid user selecting this feature
without understanding it. '--enable-tcg-interpreter' is kept in
for backward compability with scripts.
Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
RFC so it can be discarded from the series
configure | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/configure b/configure
index 71bdc523aa0..5e56fa76499 100755
--- a/configure
+++ b/configure
@@ -1121,7 +1121,8 @@ for opt do
;;
--disable-tcg-interpreter) tcg_interpreter="no"
;;
- --enable-tcg-interpreter) tcg_interpreter="yes"
+ --enable-tcg-interpreter) # backward compatibility
+ --disable-native-tcg) tcg_interpreter="yes"
;;
--disable-cap-ng) cap_ng="disabled"
;;
@@ -1753,7 +1754,7 @@ Advanced options (experts only):
--with-trace-file=NAME Full PATH,NAME of file to store traces
Default:trace-<pid>
--disable-slirp disable SLIRP userspace network connectivity
- --enable-tcg-interpreter enable TCG with bytecode interpreter (experimental and slow)
+ --disable-native-tcg enable TCG with bytecode interpreter (experimental and slow)
--enable-malloc-trim enable libc malloc_trim() for memory optimization
--oss-lib path to OSS library
--cpu=CPU Build for host CPU [$cpu]
--
2.26.2
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [RFC PATCH v2 4/4] configure: Reword --enable-tcg-interpreter as --disable-native-tcg
2021-01-22 10:58 ` [RFC PATCH v2 4/4] configure: Reword --enable-tcg-interpreter as --disable-native-tcg Philippe Mathieu-Daudé
@ 2021-01-22 11:33 ` Thomas Huth
0 siblings, 0 replies; 7+ messages in thread
From: Thomas Huth @ 2021-01-22 11:33 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Paolo Bonzini, Richard Henderson, Daniel P . Berrange, Stefan Weil
On 22/01/2021 11.58, Philippe Mathieu-Daudé wrote:
> Users might want to enable all features, without realizing some
> features have negative effect. Rename '--enable-tcg-interpreter'
> as '--disable-native-tcg' to avoid user selecting this feature
> without understanding it. '--enable-tcg-interpreter' is kept in
> for backward compability with scripts.
>
> Suggested-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> RFC so it can be discarded from the series
>
> configure | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/configure b/configure
> index 71bdc523aa0..5e56fa76499 100755
> --- a/configure
> +++ b/configure
> @@ -1121,7 +1121,8 @@ for opt do
> ;;
> --disable-tcg-interpreter) tcg_interpreter="no"
> ;;
> - --enable-tcg-interpreter) tcg_interpreter="yes"
> + --enable-tcg-interpreter) # backward compatibility
> + --disable-native-tcg) tcg_interpreter="yes"
> ;;
> --disable-cap-ng) cap_ng="disabled"
> ;;
> @@ -1753,7 +1754,7 @@ Advanced options (experts only):
> --with-trace-file=NAME Full PATH,NAME of file to store traces
> Default:trace-<pid>
> --disable-slirp disable SLIRP userspace network connectivity
> - --enable-tcg-interpreter enable TCG with bytecode interpreter (experimental and slow)
> + --disable-native-tcg enable TCG with bytecode interpreter (experimental and slow)
The more I think about it, the more I like the idea.
Reviewed-by: Thomas Huth <thuth@redhat.com>
^ permalink raw reply [flat|nested] 7+ messages in thread