From: Michal Hocko <mhocko@suse.com>

There is no existing user of the flag and the flag is dangerous because
a nested allocation context can use GFP_NOFAIL which could cause
unexpected failure. Such a code would be hard to maintain because it
could be deeper in the call chain.

PF_MEMALLOC_NORECLAIM has been added even when it was pointed out [1]
that such a allocation contex is inherently unsafe if the context
doesn't fully control all allocations called from this context.

[1] https://lore.kernel.org/all/ZcM0xtlKbAOFjv5n@tiehlicka/ (local)

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/sched.h    | 1 -
 include/linux/sched/mm.h | 7 ++-----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f8d150343d42..72dad3a6317a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h

@@ -1657,7 +1657,6 @@ extern struct pid *cad_pid;
                                                 * I am cleaning dirty pages from some other bdi. */
 #define PF_KTHREAD             0x00200000      /* I am a kernel thread */
 #define PF_RANDOMIZE           0x00400000      /* Randomize virtual address space */
-#define PF_MEMALLOC_NORECLAIM  0x00800000      /* All allocation requests will clear __GFP_DIRECT_RECLAIM */