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<title>user/sven/linux.git/include/rdma, branch v4.19.59</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2018-11-13T19:08:43Z</updated>
<entry>
<title>IB/rxe: Revise the ib_wr_opcode enum</title>
<updated>2018-11-13T19:08:43Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-14T22:33:02Z</published>
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<id>urn:sha1:3b0b2820a64f2d0e9c47ef611ac3c5c44740fe21</id>
<content type='text'>
commit 9a59739bd01f77db6fbe2955a4fce165f0f43568 upstream.

This enum has become part of the uABI, as both RXE and the
ib_uverbs_post_send() command expect userspace to supply values from this
enum. So it should be properly placed in include/uapi/rdma.

In userspace this enum is called 'enum ibv_wr_opcode' as part of
libibverbs.h. That enum defines different values for IB_WR_LOCAL_INV,
IB_WR_SEND_WITH_INV, and IB_WR_LSO. These were introduced (incorrectly, it
turns out) into libiberbs in 2015.

The kernel has changed its mind on the numbering for several of the IB_WC
values over the years, but has remained stable on IB_WR_LOCAL_INV and
below.

Based on this we can conclude that there is no real user space user of the
values beyond IB_WR_ATOMIC_FETCH_AND_ADD, as they have never worked via
rdma-core. This is confirmed by inspection, only rxe uses the kernel enum
and implements the latter operations. rxe has clearly never worked with
these attributes from userspace. Other drivers that support these opcodes
implement the functionality without calling out to the kernel.

To make IB_WR_SEND_WITH_INV and related work for RXE in userspace we
choose to renumber the IB_WR enum in the kernel to match the uABI that
userspace has bee using since before Soft RoCE was merged. This is an
overall simpler configuration for the whole software stack, and obviously
can't break anything existing.

Reported-by: Seth Howell &lt;seth.howell@intel.com&gt;
Tested-by: Seth Howell &lt;seth.howell@intel.com&gt;
Fixes: 8700e3e7c485 ("Soft RoCE driver")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma</title>
<updated>2018-08-23T22:34:48Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-23T22:34:48Z</published>
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<id>urn:sha1:1290290c922fdcefbce8984e6e44b8f4e3a169b5</id>
<content type='text'>
Pull more rdma updates from Jason Gunthorpe:
 "This is the SMC cleanup promised, a randconfig regression fix, and
  kernel oops fix.

  Summary:

   - Switch SMC over to rdma_get_gid_attr and remove the compat

   - Fix a crash in HFI1 with some BIOS's

   - Fix a randconfig failure"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  IB/ucm: fix UCM link error
  IB/hfi1: Invalid NUMA node information can cause a divide by zero
  RDMA/smc: Replace ib_query_gid with rdma_get_gid_attr
</content>
</entry>
<entry>
<title>mm, oom: distinguish blockable mode for mmu notifiers</title>
<updated>2018-08-22T17:52:44Z</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2018-08-22T04:52:33Z</published>
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<id>urn:sha1:93065ac753e4443840a057bfef4be71ec766fde9</id>
<content type='text'>
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt; # AMD notifiers
Acked-by: Leon Romanovsky &lt;leonro@mellanox.com&gt; # mlx and umem_odp
Reported-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: "David (ChunMing) Zhou" &lt;David1.Zhou@amd.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Doug Ledford &lt;dledford@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Mike Marciniszyn &lt;mike.marciniszyn@intel.com&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@intel.com&gt;
Cc: Sudeep Dutt &lt;sudeep.dutt@intel.com&gt;
Cc: Ashutosh Dixit &lt;ashutosh.dixit@intel.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
Cc: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Felix Kuehling &lt;felix.kuehling@amd.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>RDMA/smc: Replace ib_query_gid with rdma_get_gid_attr</title>
<updated>2018-08-17T22:45:51Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-17T22:45:51Z</published>
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<id>urn:sha1:b4c296f9c96420b8e7e92466ea5960f10ee20aae</id>
<content type='text'>
All RDMA ULPs should be using rdma_get_gid_attr instead of
ib_query_gid. Convert SMC to use the new API.

In the process correct some confusion with gid_type - if attr-&gt;ndev is
!NULL then gid_type can never be IB_GID_TYPE_IB by
definition. IB_GID_TYPE_ROCE shares the same enum value and is probably
what was intended here.

Reviewed-by: Parav Pandit &lt;parav@mellanox.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
</content>
</entry>
<entry>
<title>Revert "net/smc: Replace ib_query_gid with rdma_get_gid_attr"</title>
<updated>2018-08-16T20:03:34Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-15T22:52:58Z</published>
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<id>urn:sha1:92f4e77c85918eab5e5803d7e28ab89a7e6bd3a2</id>
<content type='text'>
This reverts commit ddb457c6993babbcdd41fca638b870d2a2fc3941.

The include rdma/ib_cache.h is kept, and we have to add a memset
to the compat wrapper to avoid compiler warnings in gcc-7

This revert is done to avoid extensive merge conflicts with SMC
changes in netdev during the 4.19 merge window.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'v4.18' into rdma.git for-next</title>
<updated>2018-08-16T19:12:00Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-16T19:08:18Z</published>
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<id>urn:sha1:89982f7ccee2fcd8fea7936b81eec6defbf0f131</id>
<content type='text'>
Resolve merge conflicts from the -rc cycle against the rdma.git tree:

Conflicts:
 drivers/infiniband/core/uverbs_cmd.c
  - New ifs added to ib_uverbs_ex_create_flow in -rc and for-next
  - Merge removal of file-&gt;ucontext in for-next with new code in -rc
 drivers/infiniband/core/uverbs_main.c
  - for-next removed code from ib_uverbs_write() that was modified
    in for-rc

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
</content>
</entry>
<entry>
<title>IB/uverbs: Remove struct uverbs_root_spec and all supporting code</title>
<updated>2018-08-13T15:17:19Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-10T02:14:43Z</published>
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<id>urn:sha1:51d0a2b4cfa9979fd8a59faf483b4e84587ab4ea</id>
<content type='text'>
Everything now uses the uverbs_uapi data structure.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
</content>
</entry>
<entry>
<title>IB/uverbs: Use uverbs_api to unmarshal ioctl commands</title>
<updated>2018-08-13T15:17:16Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-10T02:14:42Z</published>
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<id>urn:sha1:3a863577a7496278892360a69d90d8465733100c</id>
<content type='text'>
Convert the ioctl method syscall path to use the uverbs_api data
structures. The new uapi structure includes all the same information, just
in a different and more optimal way.

 - Use attr_bkey instead of 2 level radix trees for everything related to
   attributes. This includes the attribute storage, presence, and
   detection of missing mandatory attributes.
 - Avoid iterating over all attribute storage at finish, instead use
   find_first_bit with the attr_bkey to locate only those attrs that need
   cleanup.
 - Organize things to always run, and always rely on, cleanup. This
   avoids a bunch of tricky error unwind cases.
 - Locate the method using the radix tree, and locate the attributes
   using a very efficient incremental radix tree lookup
 - Use the precomputed destroy_bkey to handle uobject destruction
 - Use the precomputed allocation sizes and precomputed 'need_stack'
   to avoid maths in the fast path. This is optimal if userspace
   does not pass (many) unsupported attributes.

Overall this results in much better codegen for the attribute accessors,
everything is now stored in bitmaps or linear arrays indexed by attr_bkey.
The compiler can compute attr_bkey values at compile time for all method
attributes, meaning things like uverbs_attr_is_valid() now compile into
single instruction bit tests.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
</content>
</entry>
<entry>
<title>IB/uverbs: Add a simple allocator to uverbs_attr_bundle</title>
<updated>2018-08-13T15:16:08Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-10T02:14:40Z</published>
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<id>urn:sha1:461bb2eee4e162617e790c74d9b4ab10056cad7f</id>
<content type='text'>
This is similar in spirit to devm, it keeps track of any allocations
linked to this method call and ensures they are all freed when the method
exits. Further, if there is space in the internal/onstack buffer then the
allocator will hand out that memory and avoid an expensive call to
kalloc/kfree in the syscall path.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Reviewed-by: Leon Romanovsky &lt;leonro@mellanox.com&gt;
</content>
</entry>
<entry>
<title>IB/uverbs: Remove the ib_uverbs_attr pointer from each attr</title>
<updated>2018-08-10T22:06:24Z</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@mellanox.com</email>
</author>
<published>2018-08-10T02:14:39Z</published>
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<id>urn:sha1:6a1f444fefeba392d1232b408aaf5902e33e0982</id>
<content type='text'>
Memory in the bundle is valuable, do not waste it holding an 8 byte
pointer for the rare case of writing to a PTR_OUT. We can compute the
pointer by storing a small 1 byte array offset and the base address of the
uattr memory in the bundle private memory.

This also means we can access the kernel's copy of the ib_uverbs_attr, so
drop the copy of flags as well.

Since the uattr base should be private bundle information this also
de-inlines the already too big uverbs_copy_to inline and moves
create_udata into uverbs_ioctl.c so they can see the private struct
definition.

Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Reviewed-by: Leon Romanovsky &lt;leonro@mellanox.com&gt;
</content>
</entry>
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