Hi Rosen, all,
thanks for your patch. As stated, I think we shall make a change
to it, which exchanges 'num_pages' with more appropriate
'num_chunks' logic. Since I haven't received a response to my
first reply yet, I'll send an RFC patch right away. I'll
restrict it to linux-rdma list and other individuals on cc
in your patch.
Thanks,
Bernard.
On 29.03.2026 15:21, Bernard Metzler wrote:
On 27.03.2026 04:00, Rosen Penev wrote:
Simplifies allocations by using a flexible array member in this struct.
Add __counted_by to get extra runtime analysis.
Signed-off-by: Rosen Penev <[email protected]>
---
drivers/infiniband/sw/siw/siw.h | 2 +-
drivers/infiniband/sw/siw/siw_mem.c | 12 +++---------
2 files changed, 4 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/sw/siw/siw.h b/drivers/infiniband/sw/siw/siw.h
index f5fd71717b80..2b327a899a1c 100644
--- a/drivers/infiniband/sw/siw/siw.h
+++ b/drivers/infiniband/sw/siw/siw.h
@@ -119,9 +119,9 @@ struct siw_page_chunk {
struct siw_umem {
struct ib_umem *base_mem;
- struct siw_page_chunk *page_chunk;
int num_pages;
Shouldn't we replace 'num_pages' by a 'num_chunks' and change
memory allocation and release code accordingly?
u64 fp_addr; /* First page base address */
+ struct siw_page_chunk page_chunk[] __counted_by(num_pages);
};
struct siw_pble {
diff --git a/drivers/infiniband/sw/siw/siw_mem.c
b/drivers/infiniband/sw/siw/siw_mem.c
index 98c802b3ed72..08047fcf0df1 100644
--- a/drivers/infiniband/sw/siw/siw_mem.c
+++ b/drivers/infiniband/sw/siw/siw_mem.c
@@ -50,7 +50,6 @@ void siw_umem_release(struct siw_umem *umem)
kfree(umem->page_chunk[i].plist);
num_pages -= PAGES_PER_CHUNK;
}
- kfree(umem->page_chunk);
kfree(umem);
}
@@ -347,16 +346,12 @@ struct siw_umem *siw_umem_get(struct ib_device *base_dev,
u64 start,
num_pages = PAGE_ALIGN(start + len - first_page_va) >> PAGE_SHIFT;
num_chunks = (num_pages >> CHUNK_SHIFT) + 1;
- umem = kzalloc_obj(*umem);
+ umem = kzalloc_flex(*umem, page_chunk, num_chunks);
if (!umem)
return ERR_PTR(-ENOMEM);
- umem->page_chunk =
- kzalloc_objs(struct siw_page_chunk, num_chunks);
- if (!umem->page_chunk) {
- rv = -ENOMEM;
- goto err_out;
- }
+ umem->num_pages = num_pages;
+
base_mem = ib_umem_get(base_dev, start, len, rights);
if (IS_ERR(base_mem)) {
rv = PTR_ERR(base_mem);
@@ -385,7 +380,6 @@ struct siw_umem *siw_umem_get(struct ib_device *base_dev,
u64 start,
umem->page_chunk[i].plist = plist;
while (nents--) {
*plist = sg_page_iter_page(&sg_iter);
- umem->num_pages++;
num_pages--;
plist++;
if (!__sg_page_iter_next(&sg_iter))
