On Mon, 23 Apr 2018, Michal Hocko wrote: > On Mon 23-04-18 10:06:08, Mikulas Patocka wrote: > > > > > He didn't want to fix vmalloc(GFP_NOIO) > > > > > > I don't remember that conversation, so I don't know whether I agree with > > > his reasoning or not. But we are supposed to be moving away from GFP_NOIO > > > towards marking regions with memalloc_noio_save() / restore. If you do > > > that, you won't need vmalloc(GFP_NOIO). > > > > He said the same thing a year ago. And there was small progress. 6 out of > > 27 __vmalloc calls were converted to memalloc_noio_save in a year - 5 in > > infiniband and 1 in btrfs. (the whole discussion is here > > http://lkml.iu.edu/hypermail/linux/kernel/1706.3/04681.html ) > > Well this is not that easy. It requires a cooperation from maintainers. > I can only do as much. I've posted patches in the past and actively > bringing up this topic at LSFMM last two years... You're right - but you have chosen the uneasy path. Fixing __vmalloc code is easy and it doesn't require cooperation with maintainers. > > He refuses 15-line patch to fix GFP_NOIO bug because he believes that in 4 > > years, the kernel will be refactored and GFP_NOIO will be eliminated. Why > > does he have veto over this part of the code? I'd much rather argue with > > people who have constructive comments about fixing bugs than with him. > > I didn't NACK the patch AFAIR. I've said it is not a good idea longterm. > I would be much more willing to change my mind if you would back your > patch by a real bug report. Hacks are acceptable when we have a real > issue in hands. But if we want to fix potential issue then better make > it properly. Developers should fix bugs in advance, not to wait until a crash hapens, is analyzed and reported. What's the problem with 15-line hack? Is the problem that kernel developers would feel depressed when looking the source code? Other than harming developers' feelings, I don't see what kind of damange could that piece of code do. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
