OpenVZ Forum


Home » Mailing lists » Devel » [-mm PATCH 0/9] Memory controller introduction (v6)
Re: [-mm PATCH 1/9] Memory controller resource counters (v6) [message #19731 is a reply to message #19730] Mon, 20 August 2007 09:01 Go to previous messageGo to previous message
Balbir Singh is currently offline  Balbir Singh
Messages: 491
Registered: August 2006
Senior Member
Alexey Dobriyan wrote:
> On Fri, Aug 17, 2007 at 02:12:38PM +0530, Balbir Singh wrote:
>> --- /dev/null
>> +++ linux-2.6.23-rc2-mm2-balbir/kernel/res_counter.c
>> +void res_counter_init(struct res_counter *counter)
>> +{
>> +	spin_lock_init(&counter->lock);
>> +	counter->limit = (unsigned long)LONG_MAX;
> 
> why cast?
> 

These patches come from Pavel. They add to readability since
limit is unsigned long.

>> +int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
>> +{
>> +	if (counter->usage > (counter->limit - val)) {
> 
> () aren't needed.
> 

it makes the code more readable

>> +	if (WARN_ON(counter->usage < val))
>> +		val = counter->usage;
> 
> explicit if and WARN_ON(1) is clearer. I should send a patch banning such
> type of usage soon.
> 

We had a WARN_ON(1) before, but we changed it in v2 or v3 based on review
comments from Dave. I think WARN_ON(cond) is more readable than
WARN_ON(1) for the same reason as BUG_ON(cond) vs BUG_ON(1)

>> +	buf = kmalloc(nbytes + 1, GFP_KERNEL);
> 
> please, switch to fixed buffer, allocating memory depending on size
> told by userspace will beat later. Ditto for other proc writing
> functions.
> 

I agree with you in part, but the size of user input is not fixed.
Setting a fixed limit seems artificial, I'll see how this can be improved.


Thanks for the detailed review comments,

-- 
	Balbir Singh
	Linux Technology Center
	IBM, ISTL
_______________________________________________
Containers mailing list
Containers@lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/containers
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Re: [PATCH 01/29] task containersv11 basic task container framework
Next Topic: [PATCH 2/5][GFS2] Use macro instead of explicit check for mandatory locks
Goto Forum:
  


Current Time: Thu Oct 09 03:32:09 GMT 2025

Total time taken to generate the page: 0.08551 seconds