* zinf tutorial

* more megatron integration docs

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NSamyam Rajbhandari <samyamr@microsoft.com>
Co-authored-by: NShaden Smith <Shaden.Smith@microsoft.com>

* Fix UnboundLocalError

* Get full partition size

* update lr scheduler doc for doing per step or epoch update

* work

* trigger build
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

* faster flatten/unflatten with apex

* switch to cpp flatten/unflatten

* style

* better comment

* missing import

* switch to build ops at run time

* fixes
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

* e-notation for large floats

* handle ints too

* readability

* handle bool
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

We really really really need those params to be validated...
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NReza Yazdani <reyazda@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

This test has been giving us trouble for a bit, seeing nondeterministic failures, skipping for now to not break out CI. Need to revisit soon though.

* zero.Init() clarification

clarify that if `model.half()` can't fit into gpu memory `zero.Init()` is a must.

this proposal is via @samyam's clarification shared elsewhere.

Thank you.

* style

* add clarity

* style
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

Bumps [kramdown](https://github.com/gettalong/kramdown) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/gettalong/kramdown/releases)
- [Changelog](https://github.com/gettalong/kramdown/blob/master/doc/news.page)
- [Commits](https://github.com/gettalong/kramdown/commits)
Signed-off-by: Ndependabot[bot] <support@github.com>
Co-authored-by: Ndependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

security alert related to older kramdown version

* Fix zero stage2 cpu_offload when some model trainable parameters skipped in training, as in https://github.com/microsoft/DeepSpeed/issues/707

As some model trainable parameters skipped in training,
their backward hooks in self.create_reduce_and_remove_grad_hooks() will not run, 
so they have no norm_for_param_grads

* Trim space

* Trim space
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>

* see_memory_usage fixes

* didn't expect pt-1.2

* fix the order of things

* fix the order of things

* [doc] pipeline

As @g-karthik flagged in https://github.com/microsoft/DeepSpeed/pull/659#discussion_r600132598 my previous correction PR had one sentence that said the wrong thing. So this PR attempts to rectify that. 

Thank you!

* tweak

As discussed in https://github.com/microsoft/DeepSpeed/issues/662 this PR modifies the doc:
* explains what to use instead of CUDA_VISIBLE_DEVICES
* puts the `--hostfile` cl arg in the correct place in the invocation script

Fixes: https://github.com/microsoft/DeepSpeed/issues/662Co-authored-by: NJeff Rasley <jerasley@microsoft.com>

* consistent checkpoint filenaming

* backward compatible rename
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>