Re: [PATCH 0/9] memcg: cleanup per-cpu stock

[Andrew Morton]

On Sun, 16 Mar 2025 08:59:20 -0700 Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote:

> On Sat, Mar 15, 2025 at 08:57:59PM -0700, Andrew Morton wrote:
> > On Sat, 15 Mar 2025 10:49:21 -0700 Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote:
> > 
> > > 
> > > This is a cleanup series which is trying to simplify the memcg per-cpu
> > > stock code, particularly it tries to remove unnecessary dependencies on
> > > local_lock of per-cpu memcg stock. The eight patch from Vlastimil
> > > optimizes the charge path by combining the charging and accounting.
> > > 
> > > This series is based on next-20250314 plus two following patches:
> > > 
> > > Link: https://lore.kernel.org/all/20250312222552.3284173-1-shakeel.butt@xxxxxxxxx/
> > > Link: https://lore.kernel.org/all/20250313054812.2185900-1-shakeel.butt@xxxxxxxxx/
> > 
> > Unfortunately the bpf tree has been making changes in the same area of
> > memcontrol.c.  01d37228d331 ("memcg: Use trylock to access memcg
> > stock_lock.")
> > 
> > Sigh.  We're at -rc7 and I don't think it's worth working around that
> > for a cleanup series.  So I'm inclined to just defer this series until
> > the next -rc cycle.
> > 
> > If BPF merges reasonably early in the next merge window then please
> > promptly send this along and I should be able to squeak it into
> > 6.15-rc1.
> 
> Ohh. I didn't realize that try_alloc changes are causing so much trouble.
> Sorry about that.
> 
> Andrew,
> 
> could you please instead take bpf-next.git try_alloc_pages branch
> into your tree and resolve two trivial conflicts:
> 1. https://lore.kernel.org/bpf/20250311120422.1d9a8f80@xxxxxxxxxxxxxxxx/
> 2. https://lore.kernel.org/bpf/20250312145247.380c2aa5@xxxxxxxxxxxxxxxx/
> There are 7 commits there.
> You can also squash Vlastimil's fix
> "Fix the flipped condition in gfpflags_allow_spinning" into 
> "Introduce try_alloc_pages" patch or keep everything as-is.
> 
> I'll drop it from bpf-next right after.
> 
> Then Shakeel can rebase/resend his set without conflicts and everything
> will be nicely ready for the merge window.
> 
> I'll defer other bpf side things to after merge window when trees converge.

Let's just leave things as they are, please.  It's only a cleanup
series and merging cleanups after -rc7 is rather dubious even without
issues such as these.