| Message ID | 1536067356-44609-3-git-send-email-imammedo@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | deprecate incorrect CPUs topology | expand |
On Tue, Sep 04, 2018 at 03:22:36PM +0200, Igor Mammedov wrote: > commit > (5cdc9b76e3 vl.c: Remove dead assignment) > removed sockets calculation when 'sockets' weren't provided on CLI > since there wasn't any users for it back then. Exiting checks > are neither reachable > } else if (sockets * cores * threads < cpus) { > or nor triggable > if (sockets * cores * threads > max_cpus) > so we weren't noticing wrong topology since then, since users > recalculate sockets adhoc on their own. > > However with deprecation check it becomes noticable, for example > -smp 2 > will start printing warning: > "warning: Invalid CPU topology deprecated: sockets (1) * cores (1) * threads (1) != maxcpus (2)" > calculating sockets if they weren't specified. > > Fix it by returning back sockets calculation if it's omited on CLI. > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > vl.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/vl.c b/vl.c > index 7fd700e..333d638 100644 > --- a/vl.c > +++ b/vl.c > @@ -1210,11 +1210,14 @@ static void smp_parse(QemuOpts *opts) > > /* compute missing values, prefer sockets over cores over threads */ > if (cpus == 0 || sockets == 0) { > - sockets = sockets > 0 ? sockets : 1; > cores = cores > 0 ? cores : 1; > threads = threads > 0 ? threads : 1; > if (cpus == 0) { > + sockets = sockets > 0 ? sockets : 1; > cpus = cores * threads * sockets; > + } else { > + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > + sockets = !sockets ? max_cpus / (cores * threads) : sockets; > } > } else if (cores == 0) { > threads = threads > 0 ? threads : 1; > -- > 2.7.4 > > Reviewed-by: Andrew Jones <drjones@redhat.com>
On Tue, Sep 04, 2018 at 05:18:48PM +0200, Andrew Jones wrote: > On Tue, Sep 04, 2018 at 03:22:36PM +0200, Igor Mammedov wrote: > > commit > > (5cdc9b76e3 vl.c: Remove dead assignment) > > removed sockets calculation when 'sockets' weren't provided on CLI > > since there wasn't any users for it back then. Exiting checks > > are neither reachable > > } else if (sockets * cores * threads < cpus) { > > or nor triggable > > if (sockets * cores * threads > max_cpus) > > so we weren't noticing wrong topology since then, since users > > recalculate sockets adhoc on their own. > > > > However with deprecation check it becomes noticable, for example > > -smp 2 > > will start printing warning: > > "warning: Invalid CPU topology deprecated: sockets (1) * cores (1) * threads (1) != maxcpus (2)" > > calculating sockets if they weren't specified. > > > > Fix it by returning back sockets calculation if it's omited on CLI. > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > --- > > vl.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/vl.c b/vl.c > > index 7fd700e..333d638 100644 > > --- a/vl.c > > +++ b/vl.c > > @@ -1210,11 +1210,14 @@ static void smp_parse(QemuOpts *opts) > > > > /* compute missing values, prefer sockets over cores over threads */ > > if (cpus == 0 || sockets == 0) { > > - sockets = sockets > 0 ? sockets : 1; > > cores = cores > 0 ? cores : 1; > > threads = threads > 0 ? threads : 1; > > if (cpus == 0) { > > + sockets = sockets > 0 ? sockets : 1; > > cpus = cores * threads * sockets; > > + } else { > > + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > > + sockets = !sockets ? max_cpus / (cores * threads) : sockets; Why the !sockets check here? If we have reached this statement we know that (cpus == 0 || sockets == 0) is true and (cpus == 0) is false, so sockets is guaranteed to be 0. Sorry for not spotting this earlier. > > } > > } else if (cores == 0) { > > threads = threads > 0 ? threads : 1; > > -- > > 2.7.4 > > > > > > Reviewed-by: Andrew Jones <drjones@redhat.com>
On Tue, 4 Sep 2018 22:40:49 -0300 Eduardo Habkost <ehabkost@redhat.com> wrote: > On Tue, Sep 04, 2018 at 05:18:48PM +0200, Andrew Jones wrote: > > On Tue, Sep 04, 2018 at 03:22:36PM +0200, Igor Mammedov wrote: > > > commit > > > (5cdc9b76e3 vl.c: Remove dead assignment) > > > removed sockets calculation when 'sockets' weren't provided on CLI > > > since there wasn't any users for it back then. Exiting checks > > > are neither reachable > > > } else if (sockets * cores * threads < cpus) { > > > or nor triggable > > > if (sockets * cores * threads > max_cpus) > > > so we weren't noticing wrong topology since then, since users > > > recalculate sockets adhoc on their own. > > > > > > However with deprecation check it becomes noticable, for example > > > -smp 2 > > > will start printing warning: > > > "warning: Invalid CPU topology deprecated: sockets (1) * cores (1) * threads (1) != maxcpus (2)" > > > calculating sockets if they weren't specified. > > > > > > Fix it by returning back sockets calculation if it's omited on CLI. > > > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > > --- > > > vl.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/vl.c b/vl.c > > > index 7fd700e..333d638 100644 > > > --- a/vl.c > > > +++ b/vl.c > > > @@ -1210,11 +1210,14 @@ static void smp_parse(QemuOpts *opts) > > > > > > /* compute missing values, prefer sockets over cores over threads */ > > > if (cpus == 0 || sockets == 0) { > > > - sockets = sockets > 0 ? sockets : 1; > > > cores = cores > 0 ? cores : 1; > > > threads = threads > 0 ? threads : 1; > > > if (cpus == 0) { > > > + sockets = sockets > 0 ? sockets : 1; > > > cpus = cores * threads * sockets; > > > + } else { > > > + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); > > > + sockets = !sockets ? max_cpus / (cores * threads) : sockets; > > Why the !sockets check here? If we have reached this statement > we know that (cpus == 0 || sockets == 0) is true and > (cpus == 0) is false, so sockets is guaranteed to be 0. Indeed, thanks for spotting it I'll fix it up and respin > > Sorry for not spotting this earlier. > > > > } > > > } else if (cores == 0) { > > > threads = threads > 0 ? threads : 1; > > > -- > > > 2.7.4 > > > > > > > > > > Reviewed-by: Andrew Jones <drjones@redhat.com> >
diff --git a/vl.c b/vl.c index 7fd700e..333d638 100644 --- a/vl.c +++ b/vl.c @@ -1210,11 +1210,14 @@ static void smp_parse(QemuOpts *opts) /* compute missing values, prefer sockets over cores over threads */ if (cpus == 0 || sockets == 0) { - sockets = sockets > 0 ? sockets : 1; cores = cores > 0 ? cores : 1; threads = threads > 0 ? threads : 1; if (cpus == 0) { + sockets = sockets > 0 ? sockets : 1; cpus = cores * threads * sockets; + } else { + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus); + sockets = !sockets ? max_cpus / (cores * threads) : sockets; } } else if (cores == 0) { threads = threads > 0 ? threads : 1;
commit (5cdc9b76e3 vl.c: Remove dead assignment) removed sockets calculation when 'sockets' weren't provided on CLI since there wasn't any users for it back then. Exiting checks are neither reachable } else if (sockets * cores * threads < cpus) { or nor triggable if (sockets * cores * threads > max_cpus) so we weren't noticing wrong topology since then, since users recalculate sockets adhoc on their own. However with deprecation check it becomes noticable, for example -smp 2 will start printing warning: "warning: Invalid CPU topology deprecated: sockets (1) * cores (1) * threads (1) != maxcpus (2)" calculating sockets if they weren't specified. Fix it by returning back sockets calculation if it's omited on CLI. Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- vl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)