From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 12/24] task_diag: add a new group to get tasks memory
	mappings (v2)
Date: Tue, 14 Jul 2015 20:08:57 +0200
Message-ID: <20150714180857.GC8088@redhat.com>
References: <1436172445-6979-1-git-send-email-avagin@openvz.org> <1436172445-6979-13-git-send-email-avagin@openvz.org>
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To: Andrey Vagin <avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Cyrill Gorcunov <gorcunov-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>, Pavel Emelyanov <xemul-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>, Roger Luethi <rl-7uj+XXdSDtwfv37vnLkPlQ@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Arnaldo Carvalho de Melo <acme-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, David Ahern <dsahern-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>, Pavel Odintsov <pavel.odintsov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
List-Id: linux-api@vger.kernel.org

On 07/06, Andrey Vagin wrote:
>
> +static int task_vma_num(struct mm_struct *mm)
> +{
> +	struct vm_area_struct *vma;
> +	int n_vma = 0;
> +
> +	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
> +		return 0;
> +
> +	down_read(&mm->mmap_sem);
> +	for (vma = mm->mmap; vma; vma = vma->vm_next, n_vma++)
> +		;
> +
> +	up_read(&mm->mmap_sem);
> +	mmput(mm);
> +
> +	return n_vma;
> +}

Hmm. How about

	int task_vma_num(struct mm_struct *mm)
	{
		return mm->map_count;
	}

?

Oleg.