Re: [PATCH v3 07/15] mm/memory_hotplug: Introduce offline_and_remove_memory()

[Michael S. Tsirkin]

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@xxxxxxxxxxxxxxxx>
> >>> 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@xxxxxxxxxxxxxxxxxxxx>
> >> 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