linux-toradex.git/include/linux/crush, branch v4.12-rc4

crush: merge working data and scratch

2017-02-20T11:16:11+00:00

Much like Arlo Guthrie, I decided that one big pile is better than two
little piles.

Reflects ceph.git commit 95c2df6c7e0b22d2ea9d91db500cf8b9441c73ba.

Signed-off-by: Ilya Dryomov

crush: remove mutable part of CRUSH map

2017-02-20T11:16:11+00:00

Then add it to the working state. It would be very nice if we didn't
have to take a lock to calculate a crush placement. By moving the
permutation array into the working data, we can treat the CRUSH map as
immutable.

Reflects ceph.git commit cbcd039651c0569551cb90d26ce27e1432671f2a.

Signed-off-by: Ilya Dryomov

crush: add chooseleaf_stable tunable

2016-02-04T17:25:55+00:00

Add a tunable to fix the bug that chooseleaf may cause unnecessary pg
migrations when some device fails.

Reflects ceph.git commit fdb3f664448e80d984470f32f04e2e6f03ab52ec.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

crush: sync up with userspace

2015-06-25T08:49:31+00:00

.. up to ceph.git commit 1db1abc8328d ("crush: eliminate ad hoc diff
between kernel and userspace").  This fixes a bunch of recently pulled
coding style issues and makes includes a bit cleaner.

A patch "crush:Make the function crush_ln static" from Nicholas Krause
 is folded in as crush_ln() has been made static
in userspace as well.

Signed-off-by: Ilya Dryomov

crush: straw2 bucket type with an efficient 64-bit crush_ln()

2015-04-22T15:33:43+00:00

This is an improved straw bucket that correctly avoids any data movement
between items A and B when neither A nor B's weights are changed.  Said
differently, if we adjust the weight of item C (including adding it anew
or removing it completely), we will only see inputs move to or from C,
never between other items in the bucket.

Notably, there is not intermediate scaling factor that needs to be
calculated.  The mapping function is a simple function of the item weights.

The below commits were squashed together into this one (mostly to avoid
adding and then yanking a ~6000 lines worth of crush_ln_table):

- crush: add a straw2 bucket type
- crush: add crush_ln to calculate nature log efficently
- crush: improve straw2 adjustment slightly
- crush: change crush_ln to provide 32 more digits
- crush: fix crush_get_bucket_item_weight and bucket destroy for straw2
- crush/mapper: fix divide-by-0 in straw2
  (with div64_s64() for draw = ln / w and INT64_MIN -> S64_MIN - need
   to create a proper compat.h in ceph.git)

Reflects ceph.git commits 242293c908e923d474910f2b8203fa3b41eb5a53,
                          32a1ead92efcd351822d22a5fc37d159c65c1338,
                          6289912418c4a3597a11778bcf29ed5415117ad9,
                          35fcb04e2945717cf5cfe150b9fa89cb3d2303a1,
                          6445d9ee7290938de1e4ee9563912a6ab6d8ee5f,
                          b5921d55d16796e12d66ad2c4add7305f9ce2353.

Signed-off-by: Ilya Dryomov

crush: add SET_CHOOSELEAF_VARY_R step

2014-04-05T04:07:28+00:00

This lets you adjust the vary_r tunable on a per-rule basis.

Reflects ceph.git commit f944ccc20aee60a7d8da7e405ec75ad1cd449fac.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Josh Durgin

crush: add chooseleaf_vary_r tunable

2014-04-05T04:07:26+00:00

The current crush_choose_firstn code will re-use the same 'r' value for
the recursive call.  That means that if we are hitting a collision or
rejection for some reason (say, an OSD that is marked out) and need to
retry, we will keep making the same (bad) choice in that recursive
selection.

Introduce a tunable that fixes that behavior by incorporating the parent
'r' value into the recursive starting point, so that a different path
will be taken in subsequent placement attempts.

Note that this was done from the get-go for the new crush_choose_indep
algorithm.

This was exposed by a user who was seeing PGs stuck in active+remapped
after reweight-by-utilization because the up set mapped to a single OSD.

Reflects ceph.git commit a8e6c9fbf88bad056dd05d3eb790e98a5e43451a.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Josh Durgin

crush: add set_choose_local_[fallback_]tries steps

2013-12-31T18:32:26+00:00

This allows all of the tunables to be overridden by a specific rule.

Reflects ceph.git commits d129e09e57fbc61cfd4f492e3ee77d0750c9d292,
                          0497db49e5973b50df26251ed0e3f4ac7578e66e.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

crush: CHOOSE_LEAF -> CHOOSELEAF throughout

2013-12-31T18:32:24+00:00

This aligns the internal identifier names with the user-visible names in
the decompiled crush map language.

Reflects ceph.git commit caa0e22e15e4226c3671318ba1f61314bf6da2a6.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

crush: add SET_CHOOSE_TRIES rule step

2013-12-31T18:32:23+00:00

Since we can specify the recursive retries in a rule, we may as well also
specify the non-recursive tries too for completeness.

Reflects ceph.git commit d1b97462cffccc871914859eaee562f2786abfd1.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil