Re: [PATCH 2/2] sysctl: remove /proc/sys/vm/nr_pdflush_threads

[Jens Axboe]

On 10/06/2017 07:49 AM, Rakesh Pandit wrote:
> Hi Jens,
> 
> On Tue, Oct 03, 2017 at 09:16:21AM -0600, Jens Axboe wrote:
>> This tunable has been obsolete since 2.6.32, and writes to the
>> file have been failing and complaining in dmesg since then:
>>
>> nr_pdflush_threads exported in /proc is scheduled for removal
>>
>> That was 8 years ago. Remove the file ABI obsolete notice, and
>> the sysfs file.
>>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>> ---
>>  Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads | 5 -----
>>  kernel/sysctl.c                                           | 5 -----
>>  2 files changed, 10 deletions(-)
>>  delete mode 100644 Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads
>>
>> diff --git a/Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads b/Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads
>> deleted file mode 100644
>> index b0b0eeb20fe3..000000000000
>> --- a/Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads
>> +++ /dev/null
>> @@ -1,5 +0,0 @@
>> -What:		/proc/sys/vm/nr_pdflush_threads
>> -Date:		June 2012
>> -Contact:	Wanpeng Li <liwp@xxxxxxxxxxxxxxxxxx>
>> -Description: Since pdflush is replaced by per-BDI flusher, the interface of old pdflush
>> -             exported in /proc/sys/vm/ should be removed.
>> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
>> index 6648fbbb8157..a5dd8d82c253 100644
>> --- a/kernel/sysctl.c
>> +++ b/kernel/sysctl.c
>> @@ -1345,11 +1345,6 @@ static struct ctl_table vm_table[] = {
>>  		.extra1		= &zero,
>>  	},
>>  	{
>> -		.procname       = "nr_pdflush_threads",
>> -		.mode           = 0444 /* read-only */,
>> -		.proc_handler   = pdflush_proc_obsolete,
> 
> It seems you forgot to remove pdflush_proc_obsolete from:
> ./include/linux/backing-dev.h
> ./mm/backing-dev.c

Yeah, I missed that, thanks for letting me know. I've now removed them.

-- 
Jens Axboe