Dave, On 2019/07/31 8:48, Dave Chinner wrote: > On Tue, Jul 30, 2019 at 02:06:33AM +0000, Damien Le Moal wrote: >> If we had a pread_nofs()/pwrite_nofs(), that would work. Or we could define a >> RWF_NORECLAIM flag for pwritev2()/preadv2(). This last one could actually be >> the >> cleanest approach. > > Clean, yes, but I'm not sure we want to expose kernel memory reclaim > capabilities to userspace... It would be misleading, too, because we > still want to allow reclaim to occur, just not have reclaim recurse > into other filesystems....
When I wrote RWF_NORECLAIM, I was really thinking of RWF_NOFSRECLAIM. So suppressing direct reclaim recursing into another FS rather than completely disabling reclaim. Sorry for the confusion. Would this be better ? This is still application controlled, so debatable if control should be given. Most likely this would need to be limited to CAP_SYS capable user processes (e.g. root processes). I still need to check on FUSE if anything at all along these lines exists there. I will dig. Best regards. -- Damien Le Moal Western Digital Research
