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Date:   Thu, 20 Jul 2023 21:50:28 +0200
From:   =?iso-8859-2?Q?Micha=B3_Miros=B3aw?= <mirq-linux@rere.qmqm.pl>
To:     Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc:     Alex Sierra <alex.sierra@amd.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrei Vagin <avagin@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Christian Brauner <brauner@kernel.org>,
        Cyrill Gorcunov <gorcunov@gmail.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Danylo Mocherniuk <mdanylo@google.com>,
        David Hildenbrand <david@redhat.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        "Gustavo A . R . Silva" <gustavoars@kernel.org>,
        "Liam R . Howlett" <Liam.Howlett@oracle.com>,
        Matthew Wilcox <willy@infradead.org>,
        =?iso-8859-2?Q?Micha=B3_Miros=B3aw?= <emmir@google.com>,
        Mike Rapoport <rppt@kernel.org>, Nadav Amit <namit@vmware.com>,
        Pasha Tatashin <pasha.tatashin@soleen.com>,
        Paul Gofman <pgofman@codeweavers.com>,
        Peter Xu <peterx@redhat.com>, Shuah Khan <shuah@kernel.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Yang Shi <shy828301@gmail.com>,
        Yun Zhou <yun.zhou@windriver.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
        kernel@collabora.com
Subject: Re: fs/proc/task_mmu: Implement IOCTL for efficient page table
 scanning
Message-ID: <ZLmQBMympuVU2zLn@qmqm.qmqm.pl>
References: <20230713101415.108875-6-usama.anjum@collabora.com>
 <a0b5c6776b2ed91f78a7575649f8b100e58bd3a9.1689881078.git.mirq-linux@rere.qmqm.pl>
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Precedence: bulk

On Thu, Jul 20, 2023 at 09:28:52PM +0200, Micha? Miros?aw wrote:
> This is a massaged version of patch by Muhammad Usama Anjum [1]
> to illustrate my review comments and hopefully push the implementation
> efforts closer to conclusion. The changes are:
[...]
> +static void pagemap_scan_backout_range(struct pagemap_scan_private *p,
> +				       unsigned long addr, unsigned long end)
> +{
> +	struct page_region *cur_buf = &p->cur_buf;
> +
> +	if (cur_buf->start != addr) {
> +		cur_buf->end = addr;
> +	} else {
> +		cur_buf->start = cur_buf->end = 0;
> +	}
> +
> +	p->end_addr = 0;

Just noticed that this is missing:

	p->found_pages -= (end - addr) / PAGE_SIZE;

> +}
[...]

Best Regards
Micha? Miros?aw