mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory

try_alloc_pages() will not attempt to allocate memory if the system has
*any* unaccepted memory.  Memory is accepted as needed and can remain in
the system indefinitely, causing the interface to always fail.

Rather than immediately giving up, attempt to use already accepted memory
on free lists.

Pass 'alloc_flags' to cond_accept_memory() and do not accept new memory
for ALLOC_TRYLOCK requests.

Found via code inspection - only BPF uses this at present and the
runtime effects are unclear.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A. Shutemov <[email protected]>
Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation")
Cc: Alexei Starovoitov <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions