* [PATCH v2 0/1] Increase dlpar initcall priority @ 2017-12-26 12:53 Jose Ricardo Ziviani 2017-12-26 12:53 ` [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init " Jose Ricardo Ziviani 0 siblings, 1 reply; 4+ messages in thread From: Jose Ricardo Ziviani @ 2017-12-26 12:53 UTC (permalink / raw) To: linuxppc-dev; +Cc: mpe, david, benh This patch replaces the "powerpc/pseries: Use the system workqueue as fallback to hotplug workqueue". Jose Ricardo Ziviani (1): powerpc/pseries: increase pseries_dlpar_init initcall priority arch/powerpc/platforms/pseries/dlpar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.14.1 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init initcall priority 2017-12-26 12:53 [PATCH v2 0/1] Increase dlpar initcall priority Jose Ricardo Ziviani @ 2017-12-26 12:53 ` Jose Ricardo Ziviani 2018-01-02 11:46 ` Michael Ellerman 0 siblings, 1 reply; 4+ messages in thread From: Jose Ricardo Ziviani @ 2017-12-26 12:53 UTC (permalink / raw) To: linuxppc-dev; +Cc: mpe, david, benh The hotplug engine uses its own workqueue to handle IRQ requests, the problem is that such workqueue is initialized after init_ras_IRQ, which will cause a kernel panic if any hotplug interruption is issued in that period of time. This patch changes the dlpar initcall registration to make sure it will be initialized before init_ras_IRQ. Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/dlpar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c index 6e35780c5962..1f9ae1d0b2be 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -580,5 +580,5 @@ static int __init pseries_dlpar_init(void) WQ_UNBOUND, 1); return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr); } -machine_device_initcall(pseries, pseries_dlpar_init); +machine_arch_initcall(pseries, pseries_dlpar_init); -- 2.14.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init initcall priority 2017-12-26 12:53 ` [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init " Jose Ricardo Ziviani @ 2018-01-02 11:46 ` Michael Ellerman 2018-01-02 17:28 ` joserz 0 siblings, 1 reply; 4+ messages in thread From: Michael Ellerman @ 2018-01-02 11:46 UTC (permalink / raw) To: Jose Ricardo Ziviani, linuxppc-dev; +Cc: david, benh Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> writes: > The hotplug engine uses its own workqueue to handle IRQ requests, the > problem is that such workqueue is initialized after init_ras_IRQ, which > will cause a kernel panic if any hotplug interruption is issued in that > period of time. > > This patch changes the dlpar initcall registration to make sure it will > be initialized before init_ras_IRQ. Sorry I know this is already v2, but I don't think this is the best fix. There's a dependency between the registration of the IRQ in the RAS code, and the creation of the work queue in the DLPAR code, but it's currently not explicit. That's the bug. So it'd be better to just make it explicit. As a bonus we can add actual error checking of the workqueue allocation. Something like below, can you test it please? cheers diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c index 6e35780c5962..dd8b29e58a98 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -574,11 +574,26 @@ static ssize_t dlpar_show(struct class *class, struct class_attribute *attr, static CLASS_ATTR_RW(dlpar); -static int __init pseries_dlpar_init(void) +int __init dlpar_workqueue_init(void) { + if (pseries_hp_wq) + return 0; + pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue", WQ_UNBOUND, 1); + + return pseries_hp_wq ? 0 : -ENOMEM; +} + +static int __init dlpar_sysfs_init(void) +{ + int rc; + + rc = dlpar_workqueue_init(); + if (rc) + return rc; + return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr); } -machine_device_initcall(pseries, pseries_dlpar_init); +machine_device_initcall(pseries, dlpar_sysfs_init); diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h index 4470a3194311..1ae1d9f4dbe9 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -98,4 +98,6 @@ static inline unsigned long cmo_get_page_size(void) return CMO_PageSize; } +int dlpar_workqueue_init(void); + #endif /* _PSERIES_PSERIES_H */ diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index 4923ffe230cf..879a92327010 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -69,8 +69,9 @@ static int __init init_ras_IRQ(void) /* Hotplug Events */ np = of_find_node_by_path("/event-sources/hot-plug-events"); if (np != NULL) { - request_event_sources_irqs(np, ras_hotplug_interrupt, - "RAS_HOTPLUG"); + if (dlpar_workqueue_init() == 0) + request_event_sources_irqs(np, ras_hotplug_interrupt, + "RAS_HOTPLUG"); of_node_put(np); } ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init initcall priority 2018-01-02 11:46 ` Michael Ellerman @ 2018-01-02 17:28 ` joserz 0 siblings, 0 replies; 4+ messages in thread From: joserz @ 2018-01-02 17:28 UTC (permalink / raw) To: Michael Ellerman; +Cc: linuxppc-dev, benh, david On Tue, Jan 02, 2018 at 10:46:07PM +1100, Michael Ellerman wrote: > Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> writes: > > > The hotplug engine uses its own workqueue to handle IRQ requests, the > > problem is that such workqueue is initialized after init_ras_IRQ, which > > will cause a kernel panic if any hotplug interruption is issued in that > > period of time. > > > > This patch changes the dlpar initcall registration to make sure it will > > be initialized before init_ras_IRQ. > > Sorry I know this is already v2, but I don't think this is the best fix. > > There's a dependency between the registration of the IRQ in the RAS > code, and the creation of the work queue in the DLPAR code, but it's > currently not explicit. That's the bug. So it'd be better to just make > it explicit. > > As a bonus we can add actual error checking of the workqueue allocation. > > Something like below, can you test it please? sure, no problem. I'll do it. Thanks for reviewing it!!! > > cheers > > diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c > index 6e35780c5962..dd8b29e58a98 100644 > --- a/arch/powerpc/platforms/pseries/dlpar.c > +++ b/arch/powerpc/platforms/pseries/dlpar.c > @@ -574,11 +574,26 @@ static ssize_t dlpar_show(struct class *class, struct class_attribute *attr, > > static CLASS_ATTR_RW(dlpar); > > -static int __init pseries_dlpar_init(void) > +int __init dlpar_workqueue_init(void) > { > + if (pseries_hp_wq) > + return 0; > + > pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue", > WQ_UNBOUND, 1); > + > + return pseries_hp_wq ? 0 : -ENOMEM; > +} > + > +static int __init dlpar_sysfs_init(void) > +{ > + int rc; > + > + rc = dlpar_workqueue_init(); > + if (rc) > + return rc; > + > return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr); > } > -machine_device_initcall(pseries, pseries_dlpar_init); > +machine_device_initcall(pseries, dlpar_sysfs_init); > > diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h > index 4470a3194311..1ae1d9f4dbe9 100644 > --- a/arch/powerpc/platforms/pseries/pseries.h > +++ b/arch/powerpc/platforms/pseries/pseries.h > @@ -98,4 +98,6 @@ static inline unsigned long cmo_get_page_size(void) > return CMO_PageSize; > } > > +int dlpar_workqueue_init(void); > + > #endif /* _PSERIES_PSERIES_H */ > diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c > index 4923ffe230cf..879a92327010 100644 > --- a/arch/powerpc/platforms/pseries/ras.c > +++ b/arch/powerpc/platforms/pseries/ras.c > @@ -69,8 +69,9 @@ static int __init init_ras_IRQ(void) > /* Hotplug Events */ > np = of_find_node_by_path("/event-sources/hot-plug-events"); > if (np != NULL) { > - request_event_sources_irqs(np, ras_hotplug_interrupt, > - "RAS_HOTPLUG"); > + if (dlpar_workqueue_init() == 0) > + request_event_sources_irqs(np, ras_hotplug_interrupt, > + "RAS_HOTPLUG"); > of_node_put(np); > } > > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-01-02 17:28 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-12-26 12:53 [PATCH v2 0/1] Increase dlpar initcall priority Jose Ricardo Ziviani 2017-12-26 12:53 ` [PATCH v2 1/1] powerpc/pseries: increase pseries_dlpar_init " Jose Ricardo Ziviani 2018-01-02 11:46 ` Michael Ellerman 2018-01-02 17:28 ` joserz
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).