| Message ID | 1492475079-10740-1-git-send-email-tyreld@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e76ca27790a514590af782f83f6eae49e0ccf8c9 |
| Headers | show |
On Tue, 2017-04-18 at 00:24:39 UTC, Tyrel Datwyler wrote: > For cpus present at boot each logical cpu acquires a reference to the > associated device node of the core. This happens in register_cpu() which > is called by topology_init(). The result of this is that we end up with > a reference held by each thread of the core. However, these references > are never freed if the cpu core is dlpar removed. > > This patch fixes the reference leaks by acquiring and releasing the > references in the cpu hotplug callbacks un/register_cpu_online(). > With this patch symmetric reference counting is observed with both cpus > present at boot, and those dlpar added after boot. > > Cc: stable@vger.kernel.org > fixes: f86e4718f24b ("driver/core: cpu: initialize of_node in cpu's device struture") > Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/e76ca27790a514590af782f83f6eae cheers
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index c1fb255..949957b 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -710,6 +710,10 @@ static int register_cpu_online(unsigned int cpu) struct device_attribute *attrs, *pmc_attrs; int i, nattrs; + /* For cpus present at boot a reference was already grabbed in register_cpu() */ + if (!s->of_node) + s->of_node = of_get_cpu_node(cpu, NULL); + #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_SMT)) device_create_file(s, &dev_attr_smt_snooze_delay); @@ -864,6 +868,8 @@ static int unregister_cpu_online(unsigned int cpu) } #endif cacheinfo_cpu_offline(cpu); + of_node_put(s->of_node); + s->of_node = NULL; #endif /* CONFIG_HOTPLUG_CPU */ return 0; }
For cpus present at boot each logical cpu acquires a reference to the associated device node of the core. This happens in register_cpu() which is called by topology_init(). The result of this is that we end up with a reference held by each thread of the core. However, these references are never freed if the cpu core is dlpar removed. This patch fixes the reference leaks by acquiring and releasing the references in the cpu hotplug callbacks un/register_cpu_online(). With this patch symmetric reference counting is observed with both cpus present at boot, and those dlpar added after boot. Cc: stable@vger.kernel.org fixes: f86e4718f24b ("driver/core: cpu: initialize of_node in cpu's device struture") Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> --- arch/powerpc/kernel/sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+)