Messages in this thread | | | Date | Tue, 24 Apr 2012 14:30:15 -0700 | From | Andrew Morton <> | Subject | Re: [RFC] propagate gfp_t to page table alloc functions |
| |
On Tue, 24 Apr 2012 17:48:29 +1000 Nick Piggin <npiggin@gmail.com> wrote:
> > Hmm, there are several places to use GFP_NOIO and GFP_NOFS even, GFP_ATOMIC. > > I believe it's not trivial now. > > They're all buggy then. Unfortunately not through any real fault of their own.
There are gruesome problems in block/blk-throttle.c (thread "mempool, percpu, blkcg: fix percpu stat allocation and remove stats_lock"). It wants to do an alloc_percpu()->vmalloc() from the IO submission path, under GFP_NOIO.
Changing vmalloc() to take a gfp_t does make lots of sense, although I worry a bit about making vmalloc() easier to use!
I do wonder whether the whole scheme of explicitly passing a gfp_t was a mistake and that the allocation context should be part of the task context. ie: pass the allocation mode via *current. As a handy side-effect that would probably save quite some code where functions are receiving a gfp_t arg then simply passing it on to the next callee.
| |