On Tue, 2024-05-14 at 14:52 +0100, Andrew Cooper wrote:
> On 14/05/2024 1:36 pm, Leigh Brown wrote:
> > Hello,
> >
> > On 2024-05-14 13:07, Andrew Cooper wrote:
> > > On 14/05/2024 9:13 am, Leigh Brown wrote:
> > > > Although using integer comparison to compare doubles kind of
> > > > works, it's annoying to see domains slightly out of order when
> > > > sorting by cpu%.
> > > >
> > > > Add a compare_dbl() function and update compare_cpu_pct() to
> > > > call it.
> > > >
> > > > Signed-off-by: Leigh Brown <le...@solinno.co.uk>
> > > > ---
> > > > tools/xentop/xentop.c | 13 ++++++++++++-
> > > > 1 file changed, 12 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/tools/xentop/xentop.c b/tools/xentop/xentop.c
> > > > index 545bd5e96d..99199caec9 100644
> > > > --- a/tools/xentop/xentop.c
> > > > +++ b/tools/xentop/xentop.c
> > > > @@ -85,6 +85,7 @@ static void set_delay(const char *value);
> > > > static void set_prompt(const char *new_prompt, void
> > > > (*func)(const
> > > > char *));
> > > > static int handle_key(int);
> > > > static int compare(unsigned long long, unsigned long long);
> > > > +static int compare_dbl(double, double);
> > > > static int compare_domains(xenstat_domain **, xenstat_domain
> > > > **);
> > > > static unsigned long long tot_net_bytes( xenstat_domain *,
> > > > int);
> > > > static bool tot_vbd_reqs(xenstat_domain *, int, unsigned long
> > > > long *);
> > > > @@ -422,6 +423,16 @@ static int compare(unsigned long long i1,
> > > > unsigned long long i2)
> > > > return 0;
> > > > }
> > > >
> > > > +/* Compares two double precision numbers, returning -1,0,1 for
> > > > <,=,> */
> > > > +static int compare_dbl(double d1, double d2)
> > > > +{
> > > > + if(d1 < d2)
> > > > + return -1;
> > > > + if(d1 > d2)
> > > > + return 1;
> > > > + return 0;
> > > > +}
> > > > +
> > > > /* Comparison function for use with qsort. Compares two
> > > > domains
> > > > using the
> > > > * current sort field. */
> > > > static int compare_domains(xenstat_domain **domain1,
> > > > xenstat_domain
> > > > **domain2)
> > > > @@ -523,7 +534,7 @@ static double get_cpu_pct(xenstat_domain
> > > > *domain)
> > > >
> > > > static int compare_cpu_pct(xenstat_domain *domain1,
> > > > xenstat_domain
> > > > *domain2)
> > > > {
> > > > - return -compare(get_cpu_pct(domain1),
> > > > get_cpu_pct(domain2));
> > > > + return -compare_dbl(get_cpu_pct(domain1),
> > > > get_cpu_pct(domain2));
> > >
> > > Oh, we were doing an implicit double->unsigned long long
> > > conversion.
> > > Over the range 0.0 to 100.0, that ought to work as expected.
> > > What kind
> > > of out-of-order are you seeing?
> >
> > Without patch:
> >
> > xentop - 13:29:01 Xen 4.18.2
> > 13 domains: 1 running, 12 blocked, 0 paused, 0 crashed, 0 dying, 0
> > shutdown
> > Mem: 67030640k total, 33097800k used, 33932840k free CPUs: 24 @
> > 3693MHz
> > NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k)
> > MAXMEM(%)
> > icecream --b--- 2597 6.6 4194368 6.3
> > 4195328 6.3
> > xendd --b--- 4016 5.4 524268 0.8
> > 525312 0.8
> > Domain-0 -----r 1059 1.7 1048576 1.6
> > 1048576 1.6
> > neon --b--- 826 1.1 2097216 3.1
> > 2098176 3.1
> > blender --b--- 121 0.2 1048640 1.6
> > 1049600 1.6
> > bread --b--- 69 0.1 524352 0.8
> > 525312 0.8
> > bob --b--- 502 0.3 16777284 25.0
> > 16778240 25.0
> > cheese --b--- 225 0.5 1048384 1.6
> > 1049600 1.6
> > cassini --b--- 489 0.4 3145792 4.7
> > 3146752 4.7
> > chickpea --b--- 67 0.1 524352 0.8
> > 525312 0.8
> > lentil --b--- 67 0.1 262208 0.4
> > 263168 0.4
> > fusilli --b--- 159 0.2 524352 0.8
> > 525312 0.8
> > pizza --b--- 359 0.5 524352 0.8
> > 525312 0.8
> >
> > With patch:
> >
> > xentop - 13:30:17 Xen 4.18.2
> > 13 domains: 1 running, 12 blocked, 0 paused, 0 crashed, 0 dying, 0
> > shutdown
> > Mem: 67030640k total, 33097788k used, 33932852k free CPUs: 24 @
> > 3693MHz
> > NAME STATE CPU(sec) CPU(%) MEM(k) MEM(%) MAXMEM(k)
> > MAXMEM(%)
> > xendd --b--- 4020 5.7 524268 0.8
> > 525312 0.8
> > icecream --b--- 2600 3.8 4194368 6.3
> > 4195328 6.3
> > Domain-0 -----r 1060 1.5 1048576 1.6
> > 1048576 1.6
> > neon --b--- 827 1.1 2097216 3.1
> > 2098176 3.1
> > cheese --b--- 225 0.7 1048384 1.6
> > 1049600 1.6
> > pizza --b--- 359 0.5 524352 0.8
> > 525312 0.8
> > cassini --b--- 490 0.4 3145792 4.7
> > 3146752 4.7
> > fusilli --b--- 159 0.2 524352 0.8
> > 525312 0.8
> > bob --b--- 502 0.2 16777284 25.0
> > 16778240 25.0
> > blender --b--- 121 0.2 1048640 1.6
> > 1049600 1.6
> > bread --b--- 69 0.1 524352 0.8
> > 525312 0.8
> > chickpea --b--- 67 0.1 524352 0.8
> > 525312 0.8
> > lentil --b--- 67 0.1 262208 0.4
> > 263168 0.4
>
>
> Ah, so it's the rounding, and a straight cast discards the fractional
> part.
>
> I think your patch is fine, although it could do with a mention of
> why
> this goes wrong in the commit message. I'm happy to adjust on
> commit.
Feel free to merge it as I am considering it as bugfix:
Release-acked-by: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
~ Oleksii
>
> ~Andrew
