From: Jens Axboe <axboe@kernel.dk>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Ming Lei <ming.lei@redhat.com>,
linux-block@vger.kernel.org, stable@vger.kernel.org,
Mark Ray <mark.ray@hpe.com>
Subject: Re: [PATCH] blk-mq: remove blk_mq_hw_sysfs_cpus
Date: Fri, 16 Aug 2019 09:12:33 -0600 [thread overview]
Message-ID: <0b0f1017-ea52-a155-fc05-e22006813105@kernel.dk> (raw)
In-Reply-To: <20190816145435.GA3424@kroah.com>
On 8/16/19 8:54 AM, Greg KH wrote:
> On Fri, Aug 16, 2019 at 08:20:42AM -0600, Jens Axboe wrote:
>> On 8/16/19 1:48 AM, Ming Lei wrote:
>>> It is reported that sysfs buffer overflow can be triggered in case
>>> of too many CPU cores(>841 on 4K PAGE_SIZE) when showing CPUs in
>>> blk_mq_hw_sysfs_cpus_show().
>>>
>>> This info isn't useful, given users may retrieve the CPU list
>>> from sw queue entries under same kobject dir, so far not see
>>> any active users.
>>>
>>> So remove the entry as suggested by Greg.
>>
>> I think that's a bit frivolous, there could very well be scripts or
>> apps that use it. Let's just fix the overflow.
>
> As no one really knows what the format is (and the patch to fix the
> overflow changes the format of the file), I would say that it needs to
> just be dropped as it is not an example of what you should be doing in
> sysfs.
It's a list of CPUs, I think the format is quite self explanatory?
But in any case, I'm not 100% opposed to removing it, it's just not
one of those things that should be done on a whim.
--
Jens Axboe
next prev parent reply other threads:[~2019-08-16 15:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 7:48 [PATCH] blk-mq: remove blk_mq_hw_sysfs_cpus Ming Lei
2019-08-16 8:12 ` Greg KH
2019-08-16 14:20 ` Jens Axboe
2019-08-16 14:54 ` Greg KH
2019-08-16 15:12 ` Jens Axboe [this message]
2019-08-16 15:21 ` Greg KH
2019-08-16 16:08 ` Ming Lei
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