RE: [PATCH] mm, oom: normalize the adj to ensure oom_badness return a positive number

[David Rientjes]

On Tue, 4 Mar 2014, He, Bo wrote:

> Sorry, the title is confusing. Change it to: mm, oom: normalize the adj to ensure oom_badness returns a positive number

There's something seriously wrong with your email client, it's not 
replying correctly to threads so this appears as a completely new thread.  
Meanwhile, your patch was completely whitespace damaged.  Please read 
Documentation/email-clients.txt.

> We are enabling android mobiles. When running stress memory test, there is a bad issue. Some critical processes such as Healthd and watchdogd are killed, while some other processes are still alive.
> OOM should kill the tasks whose oom_score are biggest. Many processes use a minus oom_score_adj. oom_badness returns 1 for all of them and their oom_score are all 0.
> 

No, you're confusing two different things.  A negative 
/proc/pid/oom_score_adj discounts a process's memory usage in comparison 
to other processes.  If this value discounts all memory usage for every 
process, then your setting of /proc/pid/oom_score_adj is wrong.

oom_badness() returns 1 so that the oom killer may still kill these 
processes, the /proc/pid/oom_score is irrelevant to this (and the only 
reason it appears as 0 is because it already normalizes by multiplying by 
1000 / totalpages).

> The patch tries to convert the minus oom_score_adj to a positive number when calculating oom_score. oom_score can keep right process priority sequence.
> 

Nack, this patch is completely disregarding the value specified by the 
user for /proc/pid/oom_score_adj.  Your userspace should be using 
/proc/pid/oom_score_adj, not /proc/pid/oom_adj. 
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