diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/gfp_types.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h index 3de43b12209e..814bb2892f99 100644 --- a/include/linux/gfp_types.h +++ b/include/linux/gfp_types.h @@ -309,8 +309,10 @@ enum { * * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower * watermark is applied to allow access to "atomic reserves". - * The current implementation doesn't support NMI and few other strict - * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT. + * The current implementation doesn't support NMI, nor contexts that disable + * preemption under PREEMPT_RT. This includes raw_spin_lock() and plain + * preempt_disable() - see "Memory allocation" in + * Documentation/core-api/real-time/differences.rst for more info. * * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim. @@ -321,6 +323,7 @@ enum { * %GFP_NOWAIT is for kernel allocations that should not stall for direct * reclaim, start physical IO or use any filesystem callback. It is very * likely to fail to allocate memory, even for very small allocations. + * The same restrictions on calling contexts apply as for %GFP_ATOMIC. * * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages * that do not require the starting of any physical IO. |