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Subject: Re: [PATCH] kernel: sysctl: change ipfrag_high/low_thresh to
 CTL_ULONG
To:     Eric Dumazet <edumazet@google.com>
CC:     LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        "David S. Miller" <davem@davemloft.net>
References: <20190524143827.43301-1-wangkefeng.wang@huawei.com>
 <CANn89i+rSEJ3Rqd5JW-w7aLzETMX89Qgg3wne9Ae7WWDBe3yZg@mail.gmail.com>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
Message-ID: <049648ab-0e51-c079-b7c8-c9022cae20b4@huawei.com>
Date:   Sat, 25 May 2019 17:00:03 +0800
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On 2019/5/24 23:00, Eric Dumazet wrote:
> On Fri, May 24, 2019 at 7:30 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>> 3e67f106f619 ("inet: frags: break the 2GB limit for frags storage"),
>> changes ipfrag_high/low_thread 'type' from int to long, using CTL_ULONG
>> instead of CTL_INT to keep consistent.
>
> What about  compatibility with existing applications ?
> Will there sysctl() fail if they provide 32bit variable ?
>
> /proc/sys/net  files are text files, but sysctl() system call has been
> discouraged for more than a decade.

The sysctl() system call is deprecated, so the main purpose of this patch is to keep consistent,

but it does set wrong value(eg, set 16000000000 to ipfrag_high_thresh) when use sysctl().


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