lkml.org 
[lkml]   [2021]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] gfp: further document GFP_DMA32
Date
kmalloc(..., GFP_DMA32) does not return DMA32 memory
because the DMA32 kmalloc cache array is not implemented.
(Reason: there is no such user in kernel).

Put a short comment about this so people can understand this by
reading the comment.

[1] https://lists.linuxfoundation.org/pipermail/iommu/2018-December/031696.html

Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
include/linux/gfp.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index b976c4177299..c7bfaa9f3903 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -302,7 +302,9 @@ struct vm_area_struct;
* lowest zone as a type of emergency reserve.
*
* %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
- * address.
+ * address. Note that kmalloc(..., GFP_DMA32) does not return DMA32 memory
+ * because the DMA32 kmalloc cache array is not implemented.
+ * (Reason: there is no such user in kernel).
*
* %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
* do not need to be directly accessible by the kernel but that cannot
--
2.18.0
\
 
 \ /
  Last update: 2021-12-07 10:37    [W:0.034 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site