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Date: Sun, 1 Oct 2017 02:15:20 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Gargi Sharma <gs051095@gmail.com>
Cc: linux-kernel@vger.kernel.org, riel@surriel.com, julia.lawall@lip6.fr,
        akpm@linux-foundation.org, mingo@kernel.org, pasha.tatashin@oracle.com,
        ktkhai@virtuozzo.com, oleg@redhat.com
Subject: Re: [PATCH v2 1/2] pid: Replace pid bitmap implementation with IDR
 API
Message-ID: <20171001091520.GA21161@infradead.org>
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> -		task_active_pid_ns(current)->last_pid);
> +		task_active_pid_ns(current)->idr.idr_next-1);

I think we want a well documented helper for this pattern instead
of poking into the internals.

Also is last - 1 always the correct answer?  Even with idr_alloc_cyclic
we could wrap around, couldn't we?