[CC David as well] The original patch has been posted here: http://lkml.kernel.org/r/65a10261038346b1a778443fd15f0980%40SHMBX01.spreadtrum.com On Tue 20-10-15 12:27:58, Eric W. Biederman wrote: > "Hongjie Fang (方洪杰)" <Hongjie.Fang@xxxxxxxxxxxxxx> writes: > > > The oom_adj's value reading through /proc/<pid>/oom_adj is different > > with the value written into /proc/<pid>/oom_adj. > > Fix this by adding a adjustment factor. > > *Scratches my head* > > Won't changing the interpretation of what is written break existing > userspace applications that write this value? No, because they will see the same value they wrote. The current state is broken because you get a different value than you wrote. I am just wondering, how have you found this problem? Code review or have you encountered a real failure because of this? > Added a few more likely memory management suspects that might understand > what is going on here. > > Eric > > > > > Signed-off-by: Hongjie Fang <hongjie.fang@xxxxxxxxxxxxxx> > > --- > > diff --git a/fs/proc/base.c b/fs/proc/base.c > > index b25eee4..1ea0589 100644 > > --- a/fs/proc/base.c > > +++ b/fs/proc/base.c > > @@ -1043,6 +1043,7 @@ static ssize_t oom_adj_write(struct file *file, const char __user *buf, > > int oom_adj; > > unsigned long flags; > > int err; > > + int adjust; This doesn't need the function visibility. > > > > memset(buffer, 0, sizeof(buffer)); > > if (count > sizeof(buffer) - 1) > > @@ -1084,8 +1085,10 @@ static ssize_t oom_adj_write(struct file *file, const char __user *buf, > > */ > > if (oom_adj == OOM_ADJUST_MAX) > > oom_adj = OOM_SCORE_ADJ_MAX; > > - else > > - oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE; > > + else{ space after else and checkpatch will probably complain about missing { } for if... Other than that the patch looks good to me. The changelog coul be slightly improved as well. > > + adjust = oom_adj > 0 ? (-OOM_DISABLE-1) : -(-OOM_DISABLE-1); > > + oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX + adjust) / -OOM_DISABLE; > > + } > > > > if (oom_adj < task->signal->oom_score_adj && > > !capable(CAP_SYS_RESOURCE)) { > > > > -- > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>