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Date:   Tue, 26 May 2020 10:28:03 -0400
From:   Dan Schatzberg <schatzberg.dan@gmail.com>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Jens Axboe <axboe@kernel.dk>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Jan Kara <jack@suse.cz>, Amir Goldstein <amir73il@gmail.com>,
        Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>, Roman Gushchin <guro@fb.com>,
        Shakeel Butt <shakeelb@google.com>,
        Chris Down <chris@chrisdown.name>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Ingo Molnar <mingo@kernel.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
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        open list <linux-kernel@vger.kernel.org>,
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        <linux-fsdevel@vger.kernel.org>,
        "open list:CONTROL GROUP (CGROUP)" <cgroups@vger.kernel.org>,
        "open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)" 
        <linux-mm@kvack.org>
Subject: Re: [PATCH v5 0/4] Charge loop device i/o to issuing cgroup
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 <20200512133545.GA26535@infradead.org>
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On Tue, May 12, 2020 at 06:35:45AM -0700, Christoph Hellwig wrote:
> On Tue, May 12, 2020 at 09:25:21AM -0400, Dan Schatzberg wrote:
> > Seems like discussion on this patch series has died down. There's been
> > a concern raised that we could generalize infrastructure across loop,
> > md, etc. This may be possible, in the future, but it isn't clear to me
> > how this would look like. I'm inclined to fix the existing issue with
> > loop devices now (this is a problem we hit at FB) and address
> > consolidation with other cases if and when those are addressed.
> > 
> > Jens, you've expressed interest in seeing this series go through the
> > block tree so I'm interested in your perspective here. Barring any
> > concrete implementation bugs, would you be okay merging this version?
> 
> Independ of any higher level issues you need to sort out the spinlock
> mess I pointed out.

Will do - I'll split out the lock-use refactor into a separate
patch. Do you have particular concerns about re-using the existing
spinlock? Its existing use is not contended so I didn't see any harm
in extending its use. I'll add this justification to the commit
message as well, but I'm tempted to leave the re-use as is instead of
creating a new lock.