Re: [PATCH V2 2/2] mm: compaction: Limit the value of interface compact_memory

From: Vlastimil Babka
Date: Wed Mar 08 2023 - 16:55:05 EST


On 3/8/23 20:57, Luis Chamberlain wrote:
> On Wed, Mar 08, 2023 at 11:23:45AM +0100, Vlastimil Babka wrote:
>> > {
>> > - if (write)
>> > + int ret;
>> > +
>> > + ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
>> > + if (ret)
>> > + return ret;
>> > + if (write) {
>> > + pr_info("compact_nodes start\n");
>> > compact_nodes();
>> > + pr_info("compact_nodes end\n");
>>
>> I'm not sure we want to start spamming the dmesg. This would make sense
>> if we wanted to deprecate the sysctl and start hunting for remaining
>> callers to be fixed. Otherwise ftrace can be used to capture e.g. the time.
>
> Without that print, I don't think a custom proc handler is needed too,
> right? So what would simplify the code.

But we'd still call compact_nodes(), so that's not possible without a custom
handler, no?

> Luis