| Message ID | 1438593291-27109-4-git-send-email-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 2015-08-03 10:14, Alex Bennée wrote: > This doesn't just dump CPU state on translation but on every block > entrance. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > Reviewed-by: Andreas Färber <afaerber@suse.de> > > --- > v4 > - add r-b tag > --- > qemu-log.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/qemu-log.c b/qemu-log.c > index 13f3813..be8405e 100644 > --- a/qemu-log.c > +++ b/qemu-log.c > @@ -105,7 +105,7 @@ const QEMULogItem qemu_log_items[] = { > { CPU_LOG_EXEC, "exec", > "show trace before each executed TB (lots of logs)" }, > { CPU_LOG_TB_CPU, "cpu", > - "show CPU state before block translation" }, > + "show CPU registers before each executed TB (lots of logs)" }, > { CPU_LOG_MMU, "mmu", > "log MMU-related activities" }, > { CPU_LOG_PCALL, "pcall", In practice this is not true for linked TB. Should we also disable TB linking when this option is enabled?
Aurelien Jarno <aurelien@aurel32.net> writes: > On 2015-08-03 10:14, Alex Bennée wrote: >> This doesn't just dump CPU state on translation but on every block >> entrance. >> >> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> >> Reviewed-by: Andreas Färber <afaerber@suse.de> >> >> --- >> v4 >> - add r-b tag >> --- >> qemu-log.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/qemu-log.c b/qemu-log.c >> index 13f3813..be8405e 100644 >> --- a/qemu-log.c >> +++ b/qemu-log.c >> @@ -105,7 +105,7 @@ const QEMULogItem qemu_log_items[] = { >> { CPU_LOG_EXEC, "exec", >> "show trace before each executed TB (lots of logs)" }, >> { CPU_LOG_TB_CPU, "cpu", >> - "show CPU state before block translation" }, >> + "show CPU registers before each executed TB (lots of logs)" }, >> { CPU_LOG_MMU, "mmu", >> "log MMU-related activities" }, >> { CPU_LOG_PCALL, "pcall", > > In practice this is not true for linked TB. Should we also disable TB > linking when this option is enabled? Good question. I suspect yes because if you've gone to level of wanting exec tracing you'll probably get confused by the chaining. Of course it will run a lot slower then.
On 4 August 2015 at 16:11, Alex Bennée <alex.bennee@linaro.org> wrote: > Aurelien Jarno <aurelien@aurel32.net> writes: >> On 2015-08-03 10:14, Alex Bennée wrote: >> In practice this is not true for linked TB. Should we also disable TB >> linking when this option is enabled? > > Good question. I suspect yes because if you've gone to level of wanting > exec tracing you'll probably get confused by the chaining. Of course it > will run a lot slower then. Unless the bug you were trying to track down is caused by the exec chaining, of course... But yes, I think we get more people wanting chaining to be disableable. Not sure we want to tie it to the 'cpu' debug option, though -- it applies just as much to 'exec'. -- PMM
On 08/04/2015 08:15 AM, Peter Maydell wrote: > On 4 August 2015 at 16:11, Alex Bennée <alex.bennee@linaro.org> wrote: >> Aurelien Jarno <aurelien@aurel32.net> writes: >>> On 2015-08-03 10:14, Alex Bennée wrote: >>> In practice this is not true for linked TB. Should we also disable TB >>> linking when this option is enabled? >> >> Good question. I suspect yes because if you've gone to level of wanting >> exec tracing you'll probably get confused by the chaining. Of course it >> will run a lot slower then. > > Unless the bug you were trying to track down is caused by the exec > chaining, of course... But yes, I think we get more people wanting > chaining to be disableable. > > Not sure we want to tie it to the 'cpu' debug option, though -- it > applies just as much to 'exec'. Does it make more sense to have a 'nochain' debug option, and not tie it to either 'cpu' or 'exec'? It might be occasionally useful on its own, simply to determine if a bug does exist in the exec chaining. r~
Richard Henderson <rth@twiddle.net> writes: > On 08/04/2015 08:15 AM, Peter Maydell wrote: >> On 4 August 2015 at 16:11, Alex Bennée <alex.bennee@linaro.org> wrote: >>> Aurelien Jarno <aurelien@aurel32.net> writes: >>>> On 2015-08-03 10:14, Alex Bennée wrote: >>>> In practice this is not true for linked TB. Should we also disable TB >>>> linking when this option is enabled? >>> >>> Good question. I suspect yes because if you've gone to level of wanting >>> exec tracing you'll probably get confused by the chaining. Of course it >>> will run a lot slower then. >> >> Unless the bug you were trying to track down is caused by the exec >> chaining, of course... But yes, I think we get more people wanting >> chaining to be disableable. >> >> Not sure we want to tie it to the 'cpu' debug option, though -- it >> applies just as much to 'exec'. > > Does it make more sense to have a 'nochain' debug option, and not tie it to > either 'cpu' or 'exec'? It might be occasionally useful on its own, simply to > determine if a bug does exist in the exec chaining. Would that make sense as a debug option or should we have a specific set of TCG options to alter its behaviour? > > > r~
On 08/04/2015 10:22 AM, Alex Bennée wrote: > > Richard Henderson <rth@twiddle.net> writes: > >> On 08/04/2015 08:15 AM, Peter Maydell wrote: >>> On 4 August 2015 at 16:11, Alex Bennée <alex.bennee@linaro.org> wrote: >>>> Aurelien Jarno <aurelien@aurel32.net> writes: >>>>> On 2015-08-03 10:14, Alex Bennée wrote: >>>>> In practice this is not true for linked TB. Should we also disable TB >>>>> linking when this option is enabled? >>>> >>>> Good question. I suspect yes because if you've gone to level of wanting >>>> exec tracing you'll probably get confused by the chaining. Of course it >>>> will run a lot slower then. >>> >>> Unless the bug you were trying to track down is caused by the exec >>> chaining, of course... But yes, I think we get more people wanting >>> chaining to be disableable. >>> >>> Not sure we want to tie it to the 'cpu' debug option, though -- it >>> applies just as much to 'exec'. >> >> Does it make more sense to have a 'nochain' debug option, and not tie it to >> either 'cpu' or 'exec'? It might be occasionally useful on its own, simply to >> determine if a bug does exist in the exec chaining. > > Would that make sense as a debug option or should we have a specific set > of TCG options to alter its behaviour? That's what I'm saying -- probably a separate debug option is better. r~
Richard Henderson <rth@twiddle.net> writes: > On 08/04/2015 10:22 AM, Alex Bennée wrote: >> >> Richard Henderson <rth@twiddle.net> writes: >> >>> On 08/04/2015 08:15 AM, Peter Maydell wrote: >>>> On 4 August 2015 at 16:11, Alex Bennée <alex.bennee@linaro.org> wrote: >>>>> Aurelien Jarno <aurelien@aurel32.net> writes: >>>>>> On 2015-08-03 10:14, Alex Bennée wrote: >>>>>> In practice this is not true for linked TB. Should we also disable TB >>>>>> linking when this option is enabled? >>>>> >>>>> Good question. I suspect yes because if you've gone to level of wanting >>>>> exec tracing you'll probably get confused by the chaining. Of course it >>>>> will run a lot slower then. >>>> >>>> Unless the bug you were trying to track down is caused by the exec >>>> chaining, of course... But yes, I think we get more people wanting >>>> chaining to be disableable. >>>> >>>> Not sure we want to tie it to the 'cpu' debug option, though -- it >>>> applies just as much to 'exec'. >>> >>> Does it make more sense to have a 'nochain' debug option, and not tie it to >>> either 'cpu' or 'exec'? It might be occasionally useful on its own, simply to >>> determine if a bug does exist in the exec chaining. >> >> Would that make sense as a debug option or should we have a specific set >> of TCG options to alter its behaviour? > > > That's what I'm saying -- probably a separate debug option is better. Sorry I meant should we add it to -d (as in -d nochain) or have some tcg opts (--tcg nochain,blah) > > > r~
On 08/04/2015 12:08 PM, Alex Bennée wrote: >>> Would that make sense as a debug option or should we have a specific set >>> of TCG options to alter its behaviour? >> >> >> That's what I'm saying -- probably a separate debug option is better. > > Sorry I meant should we add it to -d (as in -d nochain) or have some tcg > opts (--tcg nochain,blah) I was suggesting the former: -d nochain. r~
On 4 August 2015 at 20:16, Richard Henderson <rth@twiddle.net> wrote: > On 08/04/2015 12:08 PM, Alex Bennée wrote: >>>> Would that make sense as a debug option or should we have a specific set >>>> of TCG options to alter its behaviour? >>> >>> >>> That's what I'm saying -- probably a separate debug option is better. >> >> Sorry I meant should we add it to -d (as in -d nochain) or have some tcg >> opts (--tcg nochain,blah) > > I was suggesting the former: -d nochain. Did anybody ever write the patch to add 'nochain' support? thanks -- PMM
On 09/15/2015 12:28 PM, Peter Maydell wrote: > On 4 August 2015 at 20:16, Richard Henderson <rth@twiddle.net> wrote: >> On 08/04/2015 12:08 PM, Alex Bennée wrote: >>>>> Would that make sense as a debug option or should we have a specific set >>>>> of TCG options to alter its behaviour? >>>> >>>> >>>> That's what I'm saying -- probably a separate debug option is better. >>> >>> Sorry I meant should we add it to -d (as in -d nochain) or have some tcg >>> opts (--tcg nochain,blah) >> >> I was suggesting the former: -d nochain. > > Did anybody ever write the patch to add 'nochain' support? Nope. ;-) r~
diff --git a/qemu-log.c b/qemu-log.c index 13f3813..be8405e 100644 --- a/qemu-log.c +++ b/qemu-log.c @@ -105,7 +105,7 @@ const QEMULogItem qemu_log_items[] = { { CPU_LOG_EXEC, "exec", "show trace before each executed TB (lots of logs)" }, { CPU_LOG_TB_CPU, "cpu", - "show CPU state before block translation" }, + "show CPU registers before each executed TB (lots of logs)" }, { CPU_LOG_MMU, "mmu", "log MMU-related activities" }, { CPU_LOG_PCALL, "pcall",