| Message ID | 20200507103119.11219-8-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-mem: paravirtualized memory | expand |
On Thu, May 07, 2020 at 12:31:11PM +0200, David Hildenbrand wrote: > virtio-mem wants to offline and remove a memory block once it unplugged > all subblocks (e.g., using alloc_contig_range()). Let's provide > an interface to do that from a driver. virtio-mem already supports to > offline partially unplugged memory blocks. Offlining a fully unplugged > memory block will not require to migrate any pages. All unplugged > subblocks are PageOffline() and have a reference count of 0 - so > offlining code will simply skip them. > > All we need is an interface to offline and remove the memory from kernel > module context, where we don't have access to the memory block devices > (esp. find_memory_block() and device_offline()) and the device hotplug > lock. > > To keep things simple, allow to only work on a single memory block. > > Acked-by: Michal Hocko <mhocko@suse.com> > Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: David Hildenbrand <david@redhat.com> > Cc: Oscar Salvador <osalvador@suse.com> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > Cc: Wei Yang <richard.weiyang@gmail.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Qian Cai <cai@lca.pw> > Signed-off-by: David Hildenbrand <david@redhat.com> didn't you lose Andrew Morton's ack here? > --- > include/linux/memory_hotplug.h | 1 + > mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++ > 2 files changed, 38 insertions(+) I get: error: sha1 information is lacking or useless (mm/memory_hotplug.c). error: could not build fake ancestor which version is this against? Pls post patches on top of some tag in Linus' tree if possible. > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index 7dca9cd6076b..d641828e5596 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -318,6 +318,7 @@ extern void try_offline_node(int nid); > extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); > extern int remove_memory(int nid, u64 start, u64 size); > extern void __remove_memory(int nid, u64 start, u64 size); > +extern int offline_and_remove_memory(int nid, u64 start, u64 size); > > #else > static inline void try_offline_node(int nid) {} > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 936bfe208a6e..bf1941f02a60 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1748,4 +1748,41 @@ int remove_memory(int nid, u64 start, u64 size) > return rc; > } > EXPORT_SYMBOL_GPL(remove_memory); > + > +/* > + * Try to offline and remove a memory block. Might take a long time to > + * finish in case memory is still in use. Primarily useful for memory devices > + * that logically unplugged all memory (so it's no longer in use) and want to > + * offline + remove the memory block. > + */ > +int offline_and_remove_memory(int nid, u64 start, u64 size) > +{ > + struct memory_block *mem; > + int rc = -EINVAL; > + > + if (!IS_ALIGNED(start, memory_block_size_bytes()) || > + size != memory_block_size_bytes()) > + return rc; > + > + lock_device_hotplug(); > + mem = find_memory_block(__pfn_to_section(PFN_DOWN(start))); > + if (mem) > + rc = device_offline(&mem->dev); > + /* Ignore if the device is already offline. */ > + if (rc > 0) > + rc = 0; > + > + /* > + * In case we succeeded to offline the memory block, remove it. > + * This cannot fail as it cannot get onlined in the meantime. > + */ > + if (!rc) { > + rc = try_remove_memory(nid, start, size); > + WARN_ON_ONCE(rc); > + } > + unlock_device_hotplug(); > + > + return rc; > +} > +EXPORT_SYMBOL_GPL(offline_and_remove_memory); > #endif /* CONFIG_MEMORY_HOTREMOVE */ > -- > 2.25.3
On 07.05.20 12:46, Michael S. Tsirkin wrote: > On Thu, May 07, 2020 at 12:31:11PM +0200, David Hildenbrand wrote: >> virtio-mem wants to offline and remove a memory block once it unplugged >> all subblocks (e.g., using alloc_contig_range()). Let's provide >> an interface to do that from a driver. virtio-mem already supports to >> offline partially unplugged memory blocks. Offlining a fully unplugged >> memory block will not require to migrate any pages. All unplugged >> subblocks are PageOffline() and have a reference count of 0 - so >> offlining code will simply skip them. >> >> All we need is an interface to offline and remove the memory from kernel >> module context, where we don't have access to the memory block devices >> (esp. find_memory_block() and device_offline()) and the device hotplug >> lock. >> >> To keep things simple, allow to only work on a single memory block. >> >> Acked-by: Michal Hocko <mhocko@suse.com> >> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: Oscar Salvador <osalvador@suse.com> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> >> Cc: Wei Yang <richard.weiyang@gmail.com> >> Cc: Dan Williams <dan.j.williams@intel.com> >> Cc: Qian Cai <cai@lca.pw> >> Signed-off-by: David Hildenbrand <david@redhat.com> > > > didn't you lose Andrew Morton's ack here? Yeah, thanks for noticing. > >> --- >> include/linux/memory_hotplug.h | 1 + >> mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++ >> 2 files changed, 38 insertions(+) > > I get: > > error: sha1 information is lacking or useless (mm/memory_hotplug.c). > error: could not build fake ancestor > > which version is this against? Pls post patches on top of some tag > in Linus' tree if possible. As the cover states, latest linux-next. To be precise commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, next/master) Author: Stephen Rothwell <sfr@canb.auug.org.au> Date: Thu May 7 18:11:31 2020 +1000 Add linux-next specific files for 20200507
>> I get: >> >> error: sha1 information is lacking or useless (mm/memory_hotplug.c). >> error: could not build fake ancestor >> >> which version is this against? Pls post patches on top of some tag >> in Linus' tree if possible. > > As the cover states, latest linux-next. To be precise > > commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, > next/master) > Author: Stephen Rothwell <sfr@canb.auug.org.au> > Date: Thu May 7 18:11:31 2020 +1000 > > Add linux-next specific files for 20200507 > The patches seem to apply cleanly on top of commit a811c1fa0a02c062555b54651065899437bacdbe (linus/master) Merge: b9388959ba50 16f8036086a9 Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Wed May 6 20:53:22 2020 -0700 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net I can resend based on that, after giving it a short test.
On Thu, May 07, 2020 at 01:24:38PM +0200, David Hildenbrand wrote: > On 07.05.20 12:46, Michael S. Tsirkin wrote: > > On Thu, May 07, 2020 at 12:31:11PM +0200, David Hildenbrand wrote: > >> virtio-mem wants to offline and remove a memory block once it unplugged > >> all subblocks (e.g., using alloc_contig_range()). Let's provide > >> an interface to do that from a driver. virtio-mem already supports to > >> offline partially unplugged memory blocks. Offlining a fully unplugged > >> memory block will not require to migrate any pages. All unplugged > >> subblocks are PageOffline() and have a reference count of 0 - so > >> offlining code will simply skip them. > >> > >> All we need is an interface to offline and remove the memory from kernel > >> module context, where we don't have access to the memory block devices > >> (esp. find_memory_block() and device_offline()) and the device hotplug > >> lock. > >> > >> To keep things simple, allow to only work on a single memory block. > >> > >> Acked-by: Michal Hocko <mhocko@suse.com> > >> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> > >> Cc: Andrew Morton <akpm@linux-foundation.org> > >> Cc: David Hildenbrand <david@redhat.com> > >> Cc: Oscar Salvador <osalvador@suse.com> > >> Cc: Michal Hocko <mhocko@suse.com> > >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > >> Cc: Wei Yang <richard.weiyang@gmail.com> > >> Cc: Dan Williams <dan.j.williams@intel.com> > >> Cc: Qian Cai <cai@lca.pw> > >> Signed-off-by: David Hildenbrand <david@redhat.com> > > > > > > didn't you lose Andrew Morton's ack here? > > Yeah, thanks for noticing. > > > > >> --- > >> include/linux/memory_hotplug.h | 1 + > >> mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++ > >> 2 files changed, 38 insertions(+) > > > > I get: > > > > error: sha1 information is lacking or useless (mm/memory_hotplug.c). > > error: could not build fake ancestor > > > > which version is this against? Pls post patches on top of some tag > > in Linus' tree if possible. > > As the cover states, latest linux-next. To be precise > > commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, > next/master) > Author: Stephen Rothwell <sfr@canb.auug.org.au> > Date: Thu May 7 18:11:31 2020 +1000 > > Add linux-next specific files for 20200507 > Don't base on linux-next please. Generally base on the tree you are targeting, or Linus' tree. > -- > Thanks, > > David / dhildenb
On Thu, May 07, 2020 at 01:33:23PM +0200, David Hildenbrand wrote: > >> I get: > >> > >> error: sha1 information is lacking or useless (mm/memory_hotplug.c). > >> error: could not build fake ancestor > >> > >> which version is this against? Pls post patches on top of some tag > >> in Linus' tree if possible. > > > > As the cover states, latest linux-next. To be precise > > > > commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, > > next/master) > > Author: Stephen Rothwell <sfr@canb.auug.org.au> > > Date: Thu May 7 18:11:31 2020 +1000 > > > > Add linux-next specific files for 20200507 > > > > The patches seem to apply cleanly on top of > > commit a811c1fa0a02c062555b54651065899437bacdbe (linus/master) > Merge: b9388959ba50 16f8036086a9 > Author: Linus Torvalds <torvalds@linux-foundation.org> > Date: Wed May 6 20:53:22 2020 -0700 > > Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Because you have the relevant hashes in your git tree not pruned yet. Do a new clone and they won't apply. > > I can resend based on that, after giving it a short test. > > -- > Thanks, > > David / dhildenb
On 07.05.20 13:34, Michael S. Tsirkin wrote: > On Thu, May 07, 2020 at 01:33:23PM +0200, David Hildenbrand wrote: >>>> I get: >>>> >>>> error: sha1 information is lacking or useless (mm/memory_hotplug.c). >>>> error: could not build fake ancestor >>>> >>>> which version is this against? Pls post patches on top of some tag >>>> in Linus' tree if possible. >>> >>> As the cover states, latest linux-next. To be precise >>> >>> commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, >>> next/master) >>> Author: Stephen Rothwell <sfr@canb.auug.org.au> >>> Date: Thu May 7 18:11:31 2020 +1000 >>> >>> Add linux-next specific files for 20200507 >>> >> >> The patches seem to apply cleanly on top of >> >> commit a811c1fa0a02c062555b54651065899437bacdbe (linus/master) >> Merge: b9388959ba50 16f8036086a9 >> Author: Linus Torvalds <torvalds@linux-foundation.org> >> Date: Wed May 6 20:53:22 2020 -0700 >> >> Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net > > Because you have the relevant hashes in your git tree not pruned yet. > Do a new clone and they won't apply. > Yeah, most probably, it knows how to merge. I'm used to sending all my -mm stuff based on -next, so this here is different. I'll wait a bit and then send v4 based on latest linus/master, adding the two acks and reshuffling the MAINTAINERS patch. Thanks.
On Thu, May 07, 2020 at 01:37:30PM +0200, David Hildenbrand wrote: > On 07.05.20 13:34, Michael S. Tsirkin wrote: > > On Thu, May 07, 2020 at 01:33:23PM +0200, David Hildenbrand wrote: > >>>> I get: > >>>> > >>>> error: sha1 information is lacking or useless (mm/memory_hotplug.c). > >>>> error: could not build fake ancestor > >>>> > >>>> which version is this against? Pls post patches on top of some tag > >>>> in Linus' tree if possible. > >>> > >>> As the cover states, latest linux-next. To be precise > >>> > >>> commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, > >>> next/master) > >>> Author: Stephen Rothwell <sfr@canb.auug.org.au> > >>> Date: Thu May 7 18:11:31 2020 +1000 > >>> > >>> Add linux-next specific files for 20200507 > >>> > >> > >> The patches seem to apply cleanly on top of > >> > >> commit a811c1fa0a02c062555b54651065899437bacdbe (linus/master) > >> Merge: b9388959ba50 16f8036086a9 > >> Author: Linus Torvalds <torvalds@linux-foundation.org> > >> Date: Wed May 6 20:53:22 2020 -0700 > >> > >> Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net > > > > Because you have the relevant hashes in your git tree not pruned yet. > > Do a new clone and they won't apply. > > > > Yeah, most probably, it knows how to merge. I'm used to sending all my > -mm stuff based on -next, so this here is different. Documentation/process/5.Posting.rst addresses this: Patches must be prepared against a specific version of the kernel. As a general rule, a patch should be based on the current mainline as found in Linus's git tree. When basing on mainline, start with a well-known release point - a stable or -rc release - rather than branching off the mainline at an arbitrary spot. It may become necessary to make versions against -mm, linux-next, or a subsystem tree, though, to facilitate wider testing and review. Depending on the area of your patch and what is going on elsewhere, basing a patch against these other trees can require a significant amount of work resolving conflicts and dealing with API changes. > I'll wait a bit and then send v4 based on latest linus/master, adding > the two acks and reshuffling the MAINTAINERS patch. Thanks. > > -- > Thanks, > > David / dhildenb
On 07.05.20 14:11, Michael S. Tsirkin wrote: > On Thu, May 07, 2020 at 01:37:30PM +0200, David Hildenbrand wrote: >> On 07.05.20 13:34, Michael S. Tsirkin wrote: >>> On Thu, May 07, 2020 at 01:33:23PM +0200, David Hildenbrand wrote: >>>>>> I get: >>>>>> >>>>>> error: sha1 information is lacking or useless (mm/memory_hotplug.c). >>>>>> error: could not build fake ancestor >>>>>> >>>>>> which version is this against? Pls post patches on top of some tag >>>>>> in Linus' tree if possible. >>>>> >>>>> As the cover states, latest linux-next. To be precise >>>>> >>>>> commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, >>>>> next/master) >>>>> Author: Stephen Rothwell <sfr@canb.auug.org.au> >>>>> Date: Thu May 7 18:11:31 2020 +1000 >>>>> >>>>> Add linux-next specific files for 20200507 >>>>> >>>> >>>> The patches seem to apply cleanly on top of >>>> >>>> commit a811c1fa0a02c062555b54651065899437bacdbe (linus/master) >>>> Merge: b9388959ba50 16f8036086a9 >>>> Author: Linus Torvalds <torvalds@linux-foundation.org> >>>> Date: Wed May 6 20:53:22 2020 -0700 >>>> >>>> Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net >>> >>> Because you have the relevant hashes in your git tree not pruned yet. >>> Do a new clone and they won't apply. >>> >> >> Yeah, most probably, it knows how to merge. I'm used to sending all my >> -mm stuff based on -next, so this here is different. > > > Documentation/process/5.Posting.rst addresses this: > Thanks for the info. > > Patches must be prepared against a specific version of the kernel. As a > general rule, a patch should be based on the current mainline as found in > Linus's git tree. When basing on mainline, start with a well-known release > point - a stable or -rc release - rather than branching off the mainline at > an arbitrary spot. > > It may become necessary to make versions against -mm, linux-next, or a > subsystem tree, though, to facilitate wider testing and review. Depending > on the area of your patch and what is going on elsewhere, basing a patch > against these other trees can require a significant amount of work > resolving conflicts and dealing with API changes. Yeah, but with -mm patches it is completely impractical to base them against Linus's git tree.
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 7dca9cd6076b..d641828e5596 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -318,6 +318,7 @@ extern void try_offline_node(int nid); extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); extern int remove_memory(int nid, u64 start, u64 size); extern void __remove_memory(int nid, u64 start, u64 size); +extern int offline_and_remove_memory(int nid, u64 start, u64 size); #else static inline void try_offline_node(int nid) {} diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 936bfe208a6e..bf1941f02a60 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1748,4 +1748,41 @@ int remove_memory(int nid, u64 start, u64 size) return rc; } EXPORT_SYMBOL_GPL(remove_memory); + +/* + * Try to offline and remove a memory block. Might take a long time to + * finish in case memory is still in use. Primarily useful for memory devices + * that logically unplugged all memory (so it's no longer in use) and want to + * offline + remove the memory block. + */ +int offline_and_remove_memory(int nid, u64 start, u64 size) +{ + struct memory_block *mem; + int rc = -EINVAL; + + if (!IS_ALIGNED(start, memory_block_size_bytes()) || + size != memory_block_size_bytes()) + return rc; + + lock_device_hotplug(); + mem = find_memory_block(__pfn_to_section(PFN_DOWN(start))); + if (mem) + rc = device_offline(&mem->dev); + /* Ignore if the device is already offline. */ + if (rc > 0) + rc = 0; + + /* + * In case we succeeded to offline the memory block, remove it. + * This cannot fail as it cannot get onlined in the meantime. + */ + if (!rc) { + rc = try_remove_memory(nid, start, size); + WARN_ON_ONCE(rc); + } + unlock_device_hotplug(); + + return rc; +} +EXPORT_SYMBOL_GPL(offline_and_remove_memory); #endif /* CONFIG_MEMORY_HOTREMOVE */