| Message ID | 20190507183804.5512-5-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/memory_hotplug: Factor out memory block device handling | expand |
On Tue, May 7, 2019 at 11:38 AM David Hildenbrand <david@redhat.com> wrote: > > Only memory to be added to the buddy and to be onlined/offlined by > user space using memory block devices needs (and should have!) memory > block devices. > > Factor out creation of memory block devices Create all devices after > arch_add_memory() succeeded. We can later drop the want_memblock parameter, > because it is now effectively stale. > > Only after memory block devices have been added, memory can be onlined > by user space. This implies, that memory is not visible to user space at > all before arch_add_memory() succeeded. Nice! > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > Cc: David Hildenbrand <david@redhat.com> > Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Andrew Banman <andrew.banman@hpe.com> > Cc: Oscar Salvador <osalvador@suse.de> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > Cc: Qian Cai <cai@lca.pw> > Cc: Wei Yang <richard.weiyang@gmail.com> > Cc: Arun KS <arunks@codeaurora.org> > Cc: Mathieu Malaterre <malat@debian.org> > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- > include/linux/memory.h | 2 +- > mm/memory_hotplug.c | 15 ++++----- > 3 files changed, 53 insertions(+), 34 deletions(-) > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 6e0cb4fda179..862c202a18ca 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) > return 0; > } > > +static void unregister_memory(struct memory_block *memory) > +{ > + BUG_ON(memory->dev.bus != &memory_subsys); Given this should never happen and only a future kernel developer might trip over it, do we really need to kill that developer's machine? I.e. s/BUG/WARN/? I guess an argument can be made to move such a change that to a follow-on patch since you're just preserving existing behavior, but I figure might as well address these as the code is refactored. > + > + /* drop the ref. we got via find_memory_block() */ > + put_device(&memory->dev); > + device_unregister(&memory->dev); > +} > + > /* > - * need an interface for the VM to add new memory regions, > - * but without onlining it. > + * Create memory block devices for the given memory area. Start and size > + * have to be aligned to memory block granularity. Memory block devices > + * will be initialized as offline. > */ > -int hotplug_memory_register(int nid, struct mem_section *section) > +int hotplug_memory_register(unsigned long start, unsigned long size) > { > - int ret = 0; > + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; > + unsigned long start_pfn = PFN_DOWN(start); > + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); > + unsigned long pfn; > struct memory_block *mem; > + int ret = 0; > > - mutex_lock(&mem_sysfs_mutex); > + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); > + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); Perhaps: if (WARN_ON(...)) return -EINVAL; > > - mem = find_memory_block(section); > - if (mem) { > - mem->section_count++; > - put_device(&mem->dev); > - } else { > - ret = init_memory_block(&mem, section, MEM_OFFLINE); > + mutex_lock(&mem_sysfs_mutex); > + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { > + mem = find_memory_block(__pfn_to_section(pfn)); > + if (mem) { > + WARN_ON_ONCE(false); ?? Isn't that a nop? > + put_device(&mem->dev); > + continue; > + } > + ret = init_memory_block(&mem, __pfn_to_section(pfn), > + MEM_OFFLINE); > if (ret) > - goto out; > - mem->section_count++; > + break; > + mem->section_count = memory_block_size_bytes() / > + MIN_MEMORY_BLOCK_SIZE; > + } > + if (ret) { > + end_pfn = pfn; > + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { > + mem = find_memory_block(__pfn_to_section(pfn)); > + if (!mem) > + continue; > + mem->section_count = 0; > + unregister_memory(mem); > + } > } > - > -out: > mutex_unlock(&mem_sysfs_mutex); > return ret; > } > > -static void > -unregister_memory(struct memory_block *memory) > -{ > - BUG_ON(memory->dev.bus != &memory_subsys); > - > - /* drop the ref. we got via find_memory_block() */ > - put_device(&memory->dev); > - device_unregister(&memory->dev); > -} > - > -void unregister_memory_section(struct mem_section *section) > +static int remove_memory_section(struct mem_section *section) > { > struct memory_block *mem; > > diff --git a/include/linux/memory.h b/include/linux/memory.h > index 474c7c60c8f2..95505fbb5f85 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -111,7 +111,7 @@ extern int register_memory_notifier(struct notifier_block *nb); > extern void unregister_memory_notifier(struct notifier_block *nb); > extern int register_memory_isolate_notifier(struct notifier_block *nb); > extern void unregister_memory_isolate_notifier(struct notifier_block *nb); > -int hotplug_memory_register(int nid, struct mem_section *section); > +int hotplug_memory_register(unsigned long start, unsigned long size); > extern void unregister_memory_section(struct mem_section *); > extern int memory_dev_init(void); > extern int memory_notify(unsigned long val, void *v); > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 7b5439839d67..e1637c8a0723 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -258,13 +258,7 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, > return -EEXIST; > > ret = sparse_add_one_section(nid, phys_start_pfn, altmap); > - if (ret < 0) > - return ret; > - > - if (!want_memblock) > - return 0; > - > - return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); > + return ret < 0 ? ret : 0; > } > > /* > @@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) > if (ret < 0) > goto error; > > + /* create memory block devices after memory was added */ > + ret = hotplug_memory_register(start, size); > + if (ret) { > + arch_remove_memory(nid, start, size, NULL); > + goto error; > + } > + > if (new_node) { > /* If sysfs file of new node can't be created, cpu on the node > * can't be hot-added. There is no rollback way now. > -- > 2.20.1 >
>> +static void unregister_memory(struct memory_block *memory) >> +{ >> + BUG_ON(memory->dev.bus != &memory_subsys); > > Given this should never happen and only a future kernel developer > might trip over it, do we really need to kill that developer's > machine? I.e. s/BUG/WARN/? I guess an argument can be made to move > such a change that to a follow-on patch since you're just preserving > existing behavior, but I figure might as well address these as the > code is refactored. I assume only if (WARN ...) return; makes sense then, right? > >> + >> + /* drop the ref. we got via find_memory_block() */ >> + put_device(&memory->dev); >> + device_unregister(&memory->dev); >> +} >> + >> /* >> - * need an interface for the VM to add new memory regions, >> - * but without onlining it. >> + * Create memory block devices for the given memory area. Start and size >> + * have to be aligned to memory block granularity. Memory block devices >> + * will be initialized as offline. >> */ >> -int hotplug_memory_register(int nid, struct mem_section *section) >> +int hotplug_memory_register(unsigned long start, unsigned long size) >> { >> - int ret = 0; >> + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; >> + unsigned long start_pfn = PFN_DOWN(start); >> + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); >> + unsigned long pfn; >> struct memory_block *mem; >> + int ret = 0; >> >> - mutex_lock(&mem_sysfs_mutex); >> + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); >> + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); > > Perhaps: > > if (WARN_ON(...)) > return -EINVAL; > Yes, guess this souldn't hurt. >> >> - mem = find_memory_block(section); >> - if (mem) { >> - mem->section_count++; >> - put_device(&mem->dev); >> - } else { >> - ret = init_memory_block(&mem, section, MEM_OFFLINE); >> + mutex_lock(&mem_sysfs_mutex); >> + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { >> + mem = find_memory_block(__pfn_to_section(pfn)); >> + if (mem) { >> + WARN_ON_ONCE(false); > > ?? Isn't that a nop? Yes, that makes no sense :) Thanks!
On 07.05.19 20:38, David Hildenbrand wrote: > Only memory to be added to the buddy and to be onlined/offlined by > user space using memory block devices needs (and should have!) memory > block devices. > > Factor out creation of memory block devices Create all devices after > arch_add_memory() succeeded. We can later drop the want_memblock parameter, > because it is now effectively stale. > > Only after memory block devices have been added, memory can be onlined > by user space. This implies, that memory is not visible to user space at > all before arch_add_memory() succeeded. > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > Cc: David Hildenbrand <david@redhat.com> > Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Andrew Banman <andrew.banman@hpe.com> > Cc: Oscar Salvador <osalvador@suse.de> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > Cc: Qian Cai <cai@lca.pw> > Cc: Wei Yang <richard.weiyang@gmail.com> > Cc: Arun KS <arunks@codeaurora.org> > Cc: Mathieu Malaterre <malat@debian.org> > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- > include/linux/memory.h | 2 +- > mm/memory_hotplug.c | 15 ++++----- > 3 files changed, 53 insertions(+), 34 deletions(-) > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 6e0cb4fda179..862c202a18ca 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) > return 0; > } > > +static void unregister_memory(struct memory_block *memory) > +{ > + BUG_ON(memory->dev.bus != &memory_subsys); > + > + /* drop the ref. we got via find_memory_block() */ > + put_device(&memory->dev); > + device_unregister(&memory->dev); > +} > + > /* > - * need an interface for the VM to add new memory regions, > - * but without onlining it. > + * Create memory block devices for the given memory area. Start and size > + * have to be aligned to memory block granularity. Memory block devices > + * will be initialized as offline. > */ > -int hotplug_memory_register(int nid, struct mem_section *section) > +int hotplug_memory_register(unsigned long start, unsigned long size) > { > - int ret = 0; > + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; > + unsigned long start_pfn = PFN_DOWN(start); > + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); > + unsigned long pfn; > struct memory_block *mem; > + int ret = 0; > > - mutex_lock(&mem_sysfs_mutex); > + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); > + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); > > - mem = find_memory_block(section); > - if (mem) { > - mem->section_count++; > - put_device(&mem->dev); > - } else { > - ret = init_memory_block(&mem, section, MEM_OFFLINE); > + mutex_lock(&mem_sysfs_mutex); > + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { > + mem = find_memory_block(__pfn_to_section(pfn)); > + if (mem) { > + WARN_ON_ONCE(false); > + put_device(&mem->dev); > + continue; > + } > + ret = init_memory_block(&mem, __pfn_to_section(pfn), > + MEM_OFFLINE); > if (ret) > - goto out; > - mem->section_count++; > + break; > + mem->section_count = memory_block_size_bytes() / > + MIN_MEMORY_BLOCK_SIZE; > + } > + if (ret) { > + end_pfn = pfn; > + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { > + mem = find_memory_block(__pfn_to_section(pfn)); > + if (!mem) > + continue; > + mem->section_count = 0; > + unregister_memory(mem); > + } > } > - > -out: > mutex_unlock(&mem_sysfs_mutex); > return ret; > } > > -static void > -unregister_memory(struct memory_block *memory) > -{ > - BUG_ON(memory->dev.bus != &memory_subsys); > - > - /* drop the ref. we got via find_memory_block() */ > - put_device(&memory->dev); > - device_unregister(&memory->dev); > -} > - > -void unregister_memory_section(struct mem_section *section) > +static int remove_memory_section(struct mem_section *section) > { The function change is misplaces in this patch will drop it so this patch compiles without the other patches.
On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >Only memory to be added to the buddy and to be onlined/offlined by >user space using memory block devices needs (and should have!) memory >block devices. > >Factor out creation of memory block devices Create all devices after >arch_add_memory() succeeded. We can later drop the want_memblock parameter, >because it is now effectively stale. > >Only after memory block devices have been added, memory can be onlined >by user space. This implies, that memory is not visible to user space at >all before arch_add_memory() succeeded. > >Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >Cc: "Rafael J. Wysocki" <rafael@kernel.org> >Cc: David Hildenbrand <david@redhat.com> >Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >Cc: Andrew Morton <akpm@linux-foundation.org> >Cc: Ingo Molnar <mingo@kernel.org> >Cc: Andrew Banman <andrew.banman@hpe.com> >Cc: Oscar Salvador <osalvador@suse.de> >Cc: Michal Hocko <mhocko@suse.com> >Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >Cc: Qian Cai <cai@lca.pw> >Cc: Wei Yang <richard.weiyang@gmail.com> >Cc: Arun KS <arunks@codeaurora.org> >Cc: Mathieu Malaterre <malat@debian.org> >Signed-off-by: David Hildenbrand <david@redhat.com> >--- > drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- > include/linux/memory.h | 2 +- > mm/memory_hotplug.c | 15 ++++----- > 3 files changed, 53 insertions(+), 34 deletions(-) > >diff --git a/drivers/base/memory.c b/drivers/base/memory.c >index 6e0cb4fda179..862c202a18ca 100644 >--- a/drivers/base/memory.c >+++ b/drivers/base/memory.c >@@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) > return 0; > } > >+static void unregister_memory(struct memory_block *memory) >+{ >+ BUG_ON(memory->dev.bus != &memory_subsys); >+ >+ /* drop the ref. we got via find_memory_block() */ >+ put_device(&memory->dev); >+ device_unregister(&memory->dev); >+} >+ > /* >- * need an interface for the VM to add new memory regions, >- * but without onlining it. >+ * Create memory block devices for the given memory area. Start and size >+ * have to be aligned to memory block granularity. Memory block devices >+ * will be initialized as offline. > */ >-int hotplug_memory_register(int nid, struct mem_section *section) >+int hotplug_memory_register(unsigned long start, unsigned long size) > { >- int ret = 0; >+ unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; >+ unsigned long start_pfn = PFN_DOWN(start); >+ unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); >+ unsigned long pfn; > struct memory_block *mem; >+ int ret = 0; > >- mutex_lock(&mem_sysfs_mutex); >+ BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); >+ BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); After this change, the call flow looks like this: add_memory_resource check_hotplug_memory_range hotplug_memory_register Since in check_hotplug_memory_range() has checked the boundary, do we need to check here again?
On 09.05.19 14:43, Wei Yang wrote: > On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >> Only memory to be added to the buddy and to be onlined/offlined by >> user space using memory block devices needs (and should have!) memory >> block devices. >> >> Factor out creation of memory block devices Create all devices after >> arch_add_memory() succeeded. We can later drop the want_memblock parameter, >> because it is now effectively stale. >> >> Only after memory block devices have been added, memory can be onlined >> by user space. This implies, that memory is not visible to user space at >> all before arch_add_memory() succeeded. >> >> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> Cc: "Rafael J. Wysocki" <rafael@kernel.org> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Andrew Banman <andrew.banman@hpe.com> >> Cc: Oscar Salvador <osalvador@suse.de> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >> Cc: Qian Cai <cai@lca.pw> >> Cc: Wei Yang <richard.weiyang@gmail.com> >> Cc: Arun KS <arunks@codeaurora.org> >> Cc: Mathieu Malaterre <malat@debian.org> >> Signed-off-by: David Hildenbrand <david@redhat.com> >> --- >> drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- >> include/linux/memory.h | 2 +- >> mm/memory_hotplug.c | 15 ++++----- >> 3 files changed, 53 insertions(+), 34 deletions(-) >> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index 6e0cb4fda179..862c202a18ca 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) >> return 0; >> } >> >> +static void unregister_memory(struct memory_block *memory) >> +{ >> + BUG_ON(memory->dev.bus != &memory_subsys); >> + >> + /* drop the ref. we got via find_memory_block() */ >> + put_device(&memory->dev); >> + device_unregister(&memory->dev); >> +} >> + >> /* >> - * need an interface for the VM to add new memory regions, >> - * but without onlining it. >> + * Create memory block devices for the given memory area. Start and size >> + * have to be aligned to memory block granularity. Memory block devices >> + * will be initialized as offline. >> */ >> -int hotplug_memory_register(int nid, struct mem_section *section) >> +int hotplug_memory_register(unsigned long start, unsigned long size) >> { >> - int ret = 0; >> + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; >> + unsigned long start_pfn = PFN_DOWN(start); >> + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); >> + unsigned long pfn; >> struct memory_block *mem; >> + int ret = 0; >> >> - mutex_lock(&mem_sysfs_mutex); >> + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); >> + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); > > After this change, the call flow looks like this: > > add_memory_resource > check_hotplug_memory_range > hotplug_memory_register > > Since in check_hotplug_memory_range() has checked the boundary, do we need to > check here again? > I prefer to check for such requirements explicitly in applicable places, especially if they are placed in different files. Makes code easier to get. WARN_ON_ONCE will indicate that this has to be assured by the caller. Thanks!
On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >Only memory to be added to the buddy and to be onlined/offlined by >user space using memory block devices needs (and should have!) memory >block devices. > >Factor out creation of memory block devices Create all devices after >arch_add_memory() succeeded. We can later drop the want_memblock parameter, >because it is now effectively stale. > >Only after memory block devices have been added, memory can be onlined >by user space. This implies, that memory is not visible to user space at >all before arch_add_memory() succeeded. > >Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >Cc: "Rafael J. Wysocki" <rafael@kernel.org> >Cc: David Hildenbrand <david@redhat.com> >Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >Cc: Andrew Morton <akpm@linux-foundation.org> >Cc: Ingo Molnar <mingo@kernel.org> >Cc: Andrew Banman <andrew.banman@hpe.com> >Cc: Oscar Salvador <osalvador@suse.de> >Cc: Michal Hocko <mhocko@suse.com> >Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >Cc: Qian Cai <cai@lca.pw> >Cc: Wei Yang <richard.weiyang@gmail.com> >Cc: Arun KS <arunks@codeaurora.org> >Cc: Mathieu Malaterre <malat@debian.org> >Signed-off-by: David Hildenbrand <david@redhat.com> >--- > drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- > include/linux/memory.h | 2 +- > mm/memory_hotplug.c | 15 ++++----- > 3 files changed, 53 insertions(+), 34 deletions(-) > >diff --git a/drivers/base/memory.c b/drivers/base/memory.c >index 6e0cb4fda179..862c202a18ca 100644 >--- a/drivers/base/memory.c >+++ b/drivers/base/memory.c >@@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) > return 0; > } > >+static void unregister_memory(struct memory_block *memory) >+{ >+ BUG_ON(memory->dev.bus != &memory_subsys); >+ >+ /* drop the ref. we got via find_memory_block() */ >+ put_device(&memory->dev); >+ device_unregister(&memory->dev); >+} >+ > /* >- * need an interface for the VM to add new memory regions, >- * but without onlining it. >+ * Create memory block devices for the given memory area. Start and size >+ * have to be aligned to memory block granularity. Memory block devices >+ * will be initialized as offline. > */ >-int hotplug_memory_register(int nid, struct mem_section *section) >+int hotplug_memory_register(unsigned long start, unsigned long size) > { >- int ret = 0; >+ unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; >+ unsigned long start_pfn = PFN_DOWN(start); >+ unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); >+ unsigned long pfn; > struct memory_block *mem; >+ int ret = 0; > >- mutex_lock(&mem_sysfs_mutex); >+ BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); >+ BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); > >- mem = find_memory_block(section); >- if (mem) { >- mem->section_count++; >- put_device(&mem->dev); >- } else { >- ret = init_memory_block(&mem, section, MEM_OFFLINE); >+ mutex_lock(&mem_sysfs_mutex); >+ for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { >+ mem = find_memory_block(__pfn_to_section(pfn)); >+ if (mem) { >+ WARN_ON_ONCE(false); One question here, the purpose of WARN_ON_ONCE(false) is? Would we trigger this? >+ put_device(&mem->dev); >+ continue; >+ } >+ ret = init_memory_block(&mem, __pfn_to_section(pfn), >+ MEM_OFFLINE); > if (ret) >- goto out; >- mem->section_count++; >+ break; >+ mem->section_count = memory_block_size_bytes() / >+ MIN_MEMORY_BLOCK_SIZE; Maybe we can leverage sections_per_block variable. mem->section_count = sections_per_block; >+ } >+ if (ret) { >+ end_pfn = pfn; >+ for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { >+ mem = find_memory_block(__pfn_to_section(pfn)); >+ if (!mem) >+ continue; >+ mem->section_count = 0; >+ unregister_memory(mem); >+ } > }
On 09.05.19 15:55, Wei Yang wrote: > On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >> Only memory to be added to the buddy and to be onlined/offlined by >> user space using memory block devices needs (and should have!) memory >> block devices. >> >> Factor out creation of memory block devices Create all devices after >> arch_add_memory() succeeded. We can later drop the want_memblock parameter, >> because it is now effectively stale. >> >> Only after memory block devices have been added, memory can be onlined >> by user space. This implies, that memory is not visible to user space at >> all before arch_add_memory() succeeded. >> >> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> Cc: "Rafael J. Wysocki" <rafael@kernel.org> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Andrew Banman <andrew.banman@hpe.com> >> Cc: Oscar Salvador <osalvador@suse.de> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >> Cc: Qian Cai <cai@lca.pw> >> Cc: Wei Yang <richard.weiyang@gmail.com> >> Cc: Arun KS <arunks@codeaurora.org> >> Cc: Mathieu Malaterre <malat@debian.org> >> Signed-off-by: David Hildenbrand <david@redhat.com> >> --- >> drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- >> include/linux/memory.h | 2 +- >> mm/memory_hotplug.c | 15 ++++----- >> 3 files changed, 53 insertions(+), 34 deletions(-) >> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index 6e0cb4fda179..862c202a18ca 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) >> return 0; >> } >> >> +static void unregister_memory(struct memory_block *memory) >> +{ >> + BUG_ON(memory->dev.bus != &memory_subsys); >> + >> + /* drop the ref. we got via find_memory_block() */ >> + put_device(&memory->dev); >> + device_unregister(&memory->dev); >> +} >> + >> /* >> - * need an interface for the VM to add new memory regions, >> - * but without onlining it. >> + * Create memory block devices for the given memory area. Start and size >> + * have to be aligned to memory block granularity. Memory block devices >> + * will be initialized as offline. >> */ >> -int hotplug_memory_register(int nid, struct mem_section *section) >> +int hotplug_memory_register(unsigned long start, unsigned long size) >> { >> - int ret = 0; >> + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; >> + unsigned long start_pfn = PFN_DOWN(start); >> + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); >> + unsigned long pfn; >> struct memory_block *mem; >> + int ret = 0; >> >> - mutex_lock(&mem_sysfs_mutex); >> + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); >> + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); >> >> - mem = find_memory_block(section); >> - if (mem) { >> - mem->section_count++; >> - put_device(&mem->dev); >> - } else { >> - ret = init_memory_block(&mem, section, MEM_OFFLINE); >> + mutex_lock(&mem_sysfs_mutex); >> + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { >> + mem = find_memory_block(__pfn_to_section(pfn)); >> + if (mem) { >> + WARN_ON_ONCE(false); > > One question here, the purpose of WARN_ON_ONCE(false) is? Would we trigger > this? Would happen if something goes terribly wrong. We might want to remove this once we are sure this will not happen. I replaced it in the meantime by a if (WARN_ON_ONCE(mem)) { put_device(&mem->dev); ret = -EEXIST; break; } > >> + put_device(&mem->dev); >> + continue; >> + } >> + ret = init_memory_block(&mem, __pfn_to_section(pfn), >> + MEM_OFFLINE); >> if (ret) >> - goto out; >> - mem->section_count++; >> + break; >> + mem->section_count = memory_block_size_bytes() / >> + MIN_MEMORY_BLOCK_SIZE; > > Maybe we can leverage sections_per_block variable. Most certainly if it does what I think it does :) thanks!
On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >Only memory to be added to the buddy and to be onlined/offlined by >user space using memory block devices needs (and should have!) memory >block devices. > >Factor out creation of memory block devices Create all devices after >arch_add_memory() succeeded. We can later drop the want_memblock parameter, >because it is now effectively stale. > >Only after memory block devices have been added, memory can be onlined >by user space. This implies, that memory is not visible to user space at >all before arch_add_memory() succeeded. > >Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >Cc: "Rafael J. Wysocki" <rafael@kernel.org> >Cc: David Hildenbrand <david@redhat.com> >Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >Cc: Andrew Morton <akpm@linux-foundation.org> >Cc: Ingo Molnar <mingo@kernel.org> >Cc: Andrew Banman <andrew.banman@hpe.com> >Cc: Oscar Salvador <osalvador@suse.de> >Cc: Michal Hocko <mhocko@suse.com> >Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >Cc: Qian Cai <cai@lca.pw> >Cc: Wei Yang <richard.weiyang@gmail.com> >Cc: Arun KS <arunks@codeaurora.org> >Cc: Mathieu Malaterre <malat@debian.org> >Signed-off-by: David Hildenbrand <david@redhat.com> >--- > drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- > include/linux/memory.h | 2 +- > mm/memory_hotplug.c | 15 ++++----- > 3 files changed, 53 insertions(+), 34 deletions(-) > >diff --git a/drivers/base/memory.c b/drivers/base/memory.c >index 6e0cb4fda179..862c202a18ca 100644 >--- a/drivers/base/memory.c >+++ b/drivers/base/memory.c >@@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) > return 0; > } > >+static void unregister_memory(struct memory_block *memory) >+{ >+ BUG_ON(memory->dev.bus != &memory_subsys); >+ >+ /* drop the ref. we got via find_memory_block() */ >+ put_device(&memory->dev); >+ device_unregister(&memory->dev); >+} >+ > /* >- * need an interface for the VM to add new memory regions, >- * but without onlining it. >+ * Create memory block devices for the given memory area. Start and size >+ * have to be aligned to memory block granularity. Memory block devices >+ * will be initialized as offline. > */ >-int hotplug_memory_register(int nid, struct mem_section *section) >+int hotplug_memory_register(unsigned long start, unsigned long size) One trivial suggestion about the function name. For memory_block device, sometimes we use the full name find_memory_block init_memory_block add_memory_block But sometimes we use *nick* name hotplug_memory_register register_memory unregister_memory This is a little bit confusion. Can we use one name convention here? [...] > /* >@@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) > if (ret < 0) > goto error; > >+ /* create memory block devices after memory was added */ >+ ret = hotplug_memory_register(start, size); >+ if (ret) { >+ arch_remove_memory(nid, start, size, NULL); Functionally, it works I think. But arch_remove_memory() would remove pages from zone. At this point, we just allocate section/mmap for pages, the zones are empty and pages are not connected to zone. Function zone = page_zone(page); always gets zone #0, since pages->flags is 0 at this point. This is not exact. Would we add some comment to mention this? Or we need to clean up arch_remove_memory() to take out __remove_zone()? >+ goto error; >+ } >+ > if (new_node) { > /* If sysfs file of new node can't be created, cpu on the node > * can't be hot-added. There is no rollback way now. >-- >2.20.1
On 09.05.19 16:31, Wei Yang wrote: > On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >> Only memory to be added to the buddy and to be onlined/offlined by >> user space using memory block devices needs (and should have!) memory >> block devices. >> >> Factor out creation of memory block devices Create all devices after >> arch_add_memory() succeeded. We can later drop the want_memblock parameter, >> because it is now effectively stale. >> >> Only after memory block devices have been added, memory can be onlined >> by user space. This implies, that memory is not visible to user space at >> all before arch_add_memory() succeeded. >> >> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> Cc: "Rafael J. Wysocki" <rafael@kernel.org> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Andrew Banman <andrew.banman@hpe.com> >> Cc: Oscar Salvador <osalvador@suse.de> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >> Cc: Qian Cai <cai@lca.pw> >> Cc: Wei Yang <richard.weiyang@gmail.com> >> Cc: Arun KS <arunks@codeaurora.org> >> Cc: Mathieu Malaterre <malat@debian.org> >> Signed-off-by: David Hildenbrand <david@redhat.com> >> --- >> drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- >> include/linux/memory.h | 2 +- >> mm/memory_hotplug.c | 15 ++++----- >> 3 files changed, 53 insertions(+), 34 deletions(-) >> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index 6e0cb4fda179..862c202a18ca 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) >> return 0; >> } >> >> +static void unregister_memory(struct memory_block *memory) >> +{ >> + BUG_ON(memory->dev.bus != &memory_subsys); >> + >> + /* drop the ref. we got via find_memory_block() */ >> + put_device(&memory->dev); >> + device_unregister(&memory->dev); >> +} >> + >> /* >> - * need an interface for the VM to add new memory regions, >> - * but without onlining it. >> + * Create memory block devices for the given memory area. Start and size >> + * have to be aligned to memory block granularity. Memory block devices >> + * will be initialized as offline. >> */ >> -int hotplug_memory_register(int nid, struct mem_section *section) >> +int hotplug_memory_register(unsigned long start, unsigned long size) > > One trivial suggestion about the function name. > > For memory_block device, sometimes we use the full name > > find_memory_block > init_memory_block > add_memory_block > > But sometimes we use *nick* name > > hotplug_memory_register > register_memory > unregister_memory > > This is a little bit confusion. > > Can we use one name convention here? We can just go for crate_memory_blocks() and free_memory_blocks(). Or do you have better suggestions? (I would actually even prefer "memory_block_devices", because memory blocks have different meanins) > > [...] > >> /* >> @@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) >> if (ret < 0) >> goto error; >> >> + /* create memory block devices after memory was added */ >> + ret = hotplug_memory_register(start, size); >> + if (ret) { >> + arch_remove_memory(nid, start, size, NULL); > > Functionally, it works I think. > > But arch_remove_memory() would remove pages from zone. At this point, we just > allocate section/mmap for pages, the zones are empty and pages are not > connected to zone. > > Function zone = page_zone(page); always gets zone #0, since pages->flags is 0 > at this point. This is not exact. > > Would we add some comment to mention this? Or we need to clean up > arch_remove_memory() to take out __remove_zone()? That is precisely what is on my list next (see cover letter).This is already broken when memory that was never onlined is removed again. So I am planning to fix that independently.
On Thu, May 09, 2019 at 04:58:56PM +0200, David Hildenbrand wrote: >On 09.05.19 16:31, Wei Yang wrote: >> On Tue, May 07, 2019 at 08:38:00PM +0200, David Hildenbrand wrote: >>> Only memory to be added to the buddy and to be onlined/offlined by >>> user space using memory block devices needs (and should have!) memory >>> block devices. >>> >>> Factor out creation of memory block devices Create all devices after >>> arch_add_memory() succeeded. We can later drop the want_memblock parameter, >>> because it is now effectively stale. >>> >>> Only after memory block devices have been added, memory can be onlined >>> by user space. This implies, that memory is not visible to user space at >>> all before arch_add_memory() succeeded. >>> >>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >>> Cc: "Rafael J. Wysocki" <rafael@kernel.org> >>> Cc: David Hildenbrand <david@redhat.com> >>> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> >>> Cc: Andrew Morton <akpm@linux-foundation.org> >>> Cc: Ingo Molnar <mingo@kernel.org> >>> Cc: Andrew Banman <andrew.banman@hpe.com> >>> Cc: Oscar Salvador <osalvador@suse.de> >>> Cc: Michal Hocko <mhocko@suse.com> >>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >>> Cc: Qian Cai <cai@lca.pw> >>> Cc: Wei Yang <richard.weiyang@gmail.com> >>> Cc: Arun KS <arunks@codeaurora.org> >>> Cc: Mathieu Malaterre <malat@debian.org> >>> Signed-off-by: David Hildenbrand <david@redhat.com> >>> --- >>> drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- >>> include/linux/memory.h | 2 +- >>> mm/memory_hotplug.c | 15 ++++----- >>> 3 files changed, 53 insertions(+), 34 deletions(-) >>> >>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >>> index 6e0cb4fda179..862c202a18ca 100644 >>> --- a/drivers/base/memory.c >>> +++ b/drivers/base/memory.c >>> @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) >>> return 0; >>> } >>> >>> +static void unregister_memory(struct memory_block *memory) >>> +{ >>> + BUG_ON(memory->dev.bus != &memory_subsys); >>> + >>> + /* drop the ref. we got via find_memory_block() */ >>> + put_device(&memory->dev); >>> + device_unregister(&memory->dev); >>> +} >>> + >>> /* >>> - * need an interface for the VM to add new memory regions, >>> - * but without onlining it. >>> + * Create memory block devices for the given memory area. Start and size >>> + * have to be aligned to memory block granularity. Memory block devices >>> + * will be initialized as offline. >>> */ >>> -int hotplug_memory_register(int nid, struct mem_section *section) >>> +int hotplug_memory_register(unsigned long start, unsigned long size) >> >> One trivial suggestion about the function name. >> >> For memory_block device, sometimes we use the full name >> >> find_memory_block >> init_memory_block >> add_memory_block >> >> But sometimes we use *nick* name >> >> hotplug_memory_register >> register_memory >> unregister_memory >> >> This is a little bit confusion. >> >> Can we use one name convention here? > >We can just go for > >crate_memory_blocks() and free_memory_blocks(). Or do >you have better suggestions? s/crate/create/ Looks good to me. > >(I would actually even prefer "memory_block_devices", because memory >blocks have different meanins) > Agree with you, this comes to my mind sometime ago :-) >> >> [...] >> >>> /* >>> @@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) >>> if (ret < 0) >>> goto error; >>> >>> + /* create memory block devices after memory was added */ >>> + ret = hotplug_memory_register(start, size); >>> + if (ret) { >>> + arch_remove_memory(nid, start, size, NULL); >> >> Functionally, it works I think. >> >> But arch_remove_memory() would remove pages from zone. At this point, we just >> allocate section/mmap for pages, the zones are empty and pages are not >> connected to zone. >> >> Function zone = page_zone(page); always gets zone #0, since pages->flags is 0 >> at this point. This is not exact. >> >> Would we add some comment to mention this? Or we need to clean up >> arch_remove_memory() to take out __remove_zone()? > >That is precisely what is on my list next (see cover letter).This is >already broken when memory that was never onlined is removed again. >So I am planning to fix that independently. > Sounds great :-) Hope you would cc me in the following series. > >-- > >Thanks, > >David / dhildenb
> Looks good to me. > >> >> (I would actually even prefer "memory_block_devices", because memory >> blocks have different meanins) >> > > Agree with you, this comes to my mind sometime ago :-) We have memblocks, memory_blocks ... I guess memory_block_device is unique :) > >>> >>> [...] >>> >>>> /* >>>> @@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) >>>> if (ret < 0) >>>> goto error; >>>> >>>> + /* create memory block devices after memory was added */ >>>> + ret = hotplug_memory_register(start, size); >>>> + if (ret) { >>>> + arch_remove_memory(nid, start, size, NULL); >>> >>> Functionally, it works I think. >>> >>> But arch_remove_memory() would remove pages from zone. At this point, we just >>> allocate section/mmap for pages, the zones are empty and pages are not >>> connected to zone. >>> >>> Function zone = page_zone(page); always gets zone #0, since pages->flags is 0 >>> at this point. This is not exact. >>> >>> Would we add some comment to mention this? Or we need to clean up >>> arch_remove_memory() to take out __remove_zone()? >> >> That is precisely what is on my list next (see cover letter).This is >> already broken when memory that was never onlined is removed again. >> So I am planning to fix that independently. >> > > Sounds great :-) Especially, I suspect a lot of bugs in the area of 1. Remove memory that has never been onlined 2. Remove memory that has been onlined/offlined a couple of times 3. Remove memory that has been onlined to different zones. Will see when refactoring if my intuition is right :) > > Hope you would cc me in the following series. Sure! Thanks!
diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 6e0cb4fda179..862c202a18ca 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -701,44 +701,62 @@ static int add_memory_block(int base_section_nr) return 0; } +static void unregister_memory(struct memory_block *memory) +{ + BUG_ON(memory->dev.bus != &memory_subsys); + + /* drop the ref. we got via find_memory_block() */ + put_device(&memory->dev); + device_unregister(&memory->dev); +} + /* - * need an interface for the VM to add new memory regions, - * but without onlining it. + * Create memory block devices for the given memory area. Start and size + * have to be aligned to memory block granularity. Memory block devices + * will be initialized as offline. */ -int hotplug_memory_register(int nid, struct mem_section *section) +int hotplug_memory_register(unsigned long start, unsigned long size) { - int ret = 0; + unsigned long block_nr_pages = memory_block_size_bytes() >> PAGE_SHIFT; + unsigned long start_pfn = PFN_DOWN(start); + unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT); + unsigned long pfn; struct memory_block *mem; + int ret = 0; - mutex_lock(&mem_sysfs_mutex); + BUG_ON(!IS_ALIGNED(start, memory_block_size_bytes())); + BUG_ON(!IS_ALIGNED(size, memory_block_size_bytes())); - mem = find_memory_block(section); - if (mem) { - mem->section_count++; - put_device(&mem->dev); - } else { - ret = init_memory_block(&mem, section, MEM_OFFLINE); + mutex_lock(&mem_sysfs_mutex); + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { + mem = find_memory_block(__pfn_to_section(pfn)); + if (mem) { + WARN_ON_ONCE(false); + put_device(&mem->dev); + continue; + } + ret = init_memory_block(&mem, __pfn_to_section(pfn), + MEM_OFFLINE); if (ret) - goto out; - mem->section_count++; + break; + mem->section_count = memory_block_size_bytes() / + MIN_MEMORY_BLOCK_SIZE; + } + if (ret) { + end_pfn = pfn; + for (pfn = start_pfn; pfn != end_pfn; pfn += block_nr_pages) { + mem = find_memory_block(__pfn_to_section(pfn)); + if (!mem) + continue; + mem->section_count = 0; + unregister_memory(mem); + } } - -out: mutex_unlock(&mem_sysfs_mutex); return ret; } -static void -unregister_memory(struct memory_block *memory) -{ - BUG_ON(memory->dev.bus != &memory_subsys); - - /* drop the ref. we got via find_memory_block() */ - put_device(&memory->dev); - device_unregister(&memory->dev); -} - -void unregister_memory_section(struct mem_section *section) +static int remove_memory_section(struct mem_section *section) { struct memory_block *mem; diff --git a/include/linux/memory.h b/include/linux/memory.h index 474c7c60c8f2..95505fbb5f85 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -111,7 +111,7 @@ extern int register_memory_notifier(struct notifier_block *nb); extern void unregister_memory_notifier(struct notifier_block *nb); extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); -int hotplug_memory_register(int nid, struct mem_section *section); +int hotplug_memory_register(unsigned long start, unsigned long size); extern void unregister_memory_section(struct mem_section *); extern int memory_dev_init(void); extern int memory_notify(unsigned long val, void *v); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7b5439839d67..e1637c8a0723 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -258,13 +258,7 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, return -EEXIST; ret = sparse_add_one_section(nid, phys_start_pfn, altmap); - if (ret < 0) - return ret; - - if (!want_memblock) - return 0; - - return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); + return ret < 0 ? ret : 0; } /* @@ -1106,6 +1100,13 @@ int __ref add_memory_resource(int nid, struct resource *res) if (ret < 0) goto error; + /* create memory block devices after memory was added */ + ret = hotplug_memory_register(start, size); + if (ret) { + arch_remove_memory(nid, start, size, NULL); + goto error; + } + if (new_node) { /* If sysfs file of new node can't be created, cpu on the node * can't be hot-added. There is no rollback way now.
Only memory to be added to the buddy and to be onlined/offlined by user space using memory block devices needs (and should have!) memory block devices. Factor out creation of memory block devices Create all devices after arch_add_memory() succeeded. We can later drop the want_memblock parameter, because it is now effectively stale. Only after memory block devices have been added, memory can be onlined by user space. This implies, that memory is not visible to user space at all before arch_add_memory() succeeded. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Qian Cai <cai@lca.pw> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Signed-off-by: David Hildenbrand <david@redhat.com> --- drivers/base/memory.c | 70 ++++++++++++++++++++++++++---------------- include/linux/memory.h | 2 +- mm/memory_hotplug.c | 15 ++++----- 3 files changed, 53 insertions(+), 34 deletions(-)