lkml.org 
[lkml]   [2014]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm, hugetlb: move the error handle logic out of normal code path
On Thu, 15 May 2014 11:01:42 +0200 Michal Hocko <mhocko@suse.cz> wrote:

> On Wed 14-05-14 15:10:59, Jianyu Zhan wrote:
> > alloc_huge_page() now mixes normal code path with error handle logic.
> > This patches move out the error handle logic, to make normal code
> > path more clean and redue code duplicate.
>
> I don't know. Part of the function returns and cleans up on its own and
> other part relies on clean up labels. This is not so much nicer than the
> previous state.

That's actually a common pattern:

foo()
{
if (check which doesn't change any state)
return -Efoo;
if (another check which doesn't change any state)
return -Ebar;

do_something_which_changes_state()

if (another check)
goto undo_that_state_chage;
...

undo_that_state_change:
...
}


This ties into the main reason why we use all these gotos: to support
evolution of the code. With multiple return points we risk later
adding resource leaks and locking errors. Plus the code becomes more
and more duplicative and spaghettified.




\
 
 \ /
  Last update: 2014-05-16 01:01    [W:0.075 / U:0.836 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site