If dma_direct_alloc() alloc memory in size of 64MB, the inner function
dma_common_contiguous_remap() will allocate 128KB memory by invoking
the function kmalloc_array(). and the kmalloc_array seems to fail to try to
allocate 128KB mem. work around by doing kvmalloc_array instead.
Signed-off-by: Gao Xu <[email protected]>
---
kernel/dma/remap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index b45266680..27596f3b4 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -43,13 +43,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
void *vaddr;
int i;
- pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
+ pages = kvmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
if (!pages)
return NULL;
for (i = 0; i < count; i++)
pages[i] = nth_page(page, i);
vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
- kfree(pages);
+ kvfree(pages);
return vaddr;
}
--
2.17.1
Please help to review, thanks.
-----Original Message-----
From: gaoxu 00016977
Sent: 2023??5??6?? 15:34
To: '[email protected]' <[email protected]>; '[email protected]' <[email protected]>
Cc: '[email protected]' <[email protected]>; '[email protected]' <[email protected]>; '[email protected]' <[email protected]>; '[email protected]' <[email protected]>; yipengxiang 00013268 <[email protected]>; wangbintian 00013160 <[email protected]>; hanfeng 00012985 <[email protected]>
Subject: [PATCH] dma-remap: Use kvmalloc_array/kvfree for larger dma memory remap
If dma_direct_alloc() alloc memory in size of 64MB, the inner function
dma_common_contiguous_remap() will allocate 128KB memory by invoking the function kmalloc_array(). and the kmalloc_array seems to fail to try to allocate 128KB mem. work around by doing kvmalloc_array instead.
Signed-off-by: Gao Xu <[email protected]>
---
kernel/dma/remap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index b45266680..27596f3b4 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -43,13 +43,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
void *vaddr;
int i;
- pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
+ pages = kvmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
if (!pages)
return NULL;
for (i = 0; i < count; i++)
pages[i] = nth_page(page, i);
vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
- kfree(pages);
+ kvfree(pages);
return vaddr;
}
--
2.17.1
On Sat, May 6, 2023 at 12:33 AM gaoxu 00016977 <[email protected]> wrote:
>
> If dma_direct_alloc() alloc memory in size of 64MB, the inner function
> dma_common_contiguous_remap() will allocate 128KB memory by invoking
> the function kmalloc_array(). and the kmalloc_array seems to fail to try to
> allocate 128KB mem. work around by doing kvmalloc_array instead.
On systems like Android it's not unusual for order 5 allocation to
fail. The change seems safe to me with no downside since kvmalloc will
try kmalloc first.
>
> Signed-off-by: Gao Xu <[email protected]>
Reviewed-by: Suren Baghdasaryan <[email protected]>
> ---
> kernel/dma/remap.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index b45266680..27596f3b4 100644
> --- a/kernel/dma/remap.c
> +++ b/kernel/dma/remap.c
> @@ -43,13 +43,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> void *vaddr;
> int i;
>
> - pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
> + pages = kvmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
> if (!pages)
> return NULL;
> for (i = 0; i < count; i++)
> pages[i] = nth_page(page, i);
> vaddr = vmap(pages, count, VM_DMA_COHERENT, prot);
> - kfree(pages);
> + kvfree(pages);
>
> return vaddr;
> }
> --
> 2.17.1
>