Messages in this thread | | | From | "Zengtao (B)" <> | Subject | RE: [PATCH v2] cpu-topology: Skip the exist but not possible cpu nodes | Date | Mon, 13 Jan 2020 12:06:11 +0000 |
| |
> -----Original Message----- > From: Sudeep Holla [mailto:sudeep.holla@arm.com] > Sent: Monday, January 13, 2020 6:19 PM > To: Zengtao (B) > Cc: Linuxarm; Greg Kroah-Hartman; Rafael J. Wysocki; Sudeep Holla; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH v2] cpu-topology: Skip the exist but not possible cpu > nodes > > On Sat, Jan 11, 2020 at 02:53:40PM +0800, Zeng Tao wrote: > > When CONFIG_NR_CPUS is smaller than the cpu nodes defined in the > device > > tree, all the cpu nodes parsing will fail. > > And this is not reasonable for a legal device tree configs. > > In this patch, skip such cpu nodes rather than return an error. > > With CONFIG_NR_CPUS = 128 and cpus nodes num in device tree is > 130, > > The following warning messages will be print during boot: > > CPU node for /cpus/cpu@128 exist but the possible cpu range > is :0-127 > > CPU node for /cpus/cpu@129 exist but the possible cpu range > is :0-127 > > CPU node for /cpus/cpu@130 exist but the possible cpu range > is :0-127 > > > > Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> > > --- > > Changelog: > > v1->v2: > > -Remove redundant -ENODEV assignment in get_cpu_for_node > > -Add comment to describe the get_cpu_for_node return values > > -Add skip process for cpu threads > > -Update the commit log with more detail > > --- > > drivers/base/arch_topology.c | 37 > +++++++++++++++++++++++++++++-------- > > 1 file changed, 29 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/base/arch_topology.c > b/drivers/base/arch_topology.c > > index 5fe44b3..01f0e21 100644 > > --- a/drivers/base/arch_topology.c > > +++ b/drivers/base/arch_topology.c > > @@ -248,22 +248,44 @@ core_initcall(free_raw_capacity); > > #endif > > > > #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) > > +/* > > + * This function returns the logic cpu number of the node. > > + * There are totally three kinds of return values: > > + * (1) logic cpu number which is > 0. > > + * (2) -ENDEV when the node is valid one which can be found in the > device tree > > + * but there is no possible cpu nodes to match, when the > CONFIG_NR_CPUS is > > + * smaller than cpus node numbers in device tree, this will happen. > It's > > + * suggested to just ignore this case. > > s/ENDEV/ENODEV/ Good catch, thanks.
> > Also as I mentioned earlier, I prefer not to add any extra logic here > other than the above comment to make it explicit. This triggers > unnecessary > warnings when someone boots with limited CPUs for valid reasons. >
So , what 's your suggestion here? Just keep the comments but remove the warning message print? > > > + * (3) -EINVAL when other errors occur. > > + */ > > static int __init get_cpu_for_node(struct device_node *node) > > { > > - struct device_node *cpu_node; > > + struct device_node *cpu_node, *t; > > int cpu; > > + bool found = false; > > > > cpu_node = of_parse_phandle(node, "cpu", 0); > > if (!cpu_node) > > - return -1; > > + return -EINVAL; > > + > > + for_each_of_cpu_node(t) > > + if (t == cpu_node) { > > + found = true; > > + break; > > + } > > + > > + if (!found) { > > + pr_crit("Unable to find CPU node for %pOF\n", cpu_node); > > + return -EINVAL; > > + } > > > > cpu = of_cpu_node_to_id(cpu_node); > > if (cpu >= 0) > > topology_parse_cpu_capacity(cpu_node, cpu); > > else > > - pr_crit("Unable to find CPU node for %pOF\n", cpu_node); > > + pr_warn("CPU node for %pOF exist but the possible cpu range > is :%*pbl\n", > > + cpu_node, cpumask_pr_args(cpu_possible_mask)); > > > > - of_node_put(cpu_node); > > Why is this dropped ?
It's unnecessary here since no one get the node ref.
Regards Zengtao
| |