Re: [PATCH v1 19/36] io_uring/zcrx: remove nth_page() usage within folio
From: Lorenzo Stoakes <hidden>
Date: 2025-08-28 16:49:54
Also in:
dri-devel, intel-gfx, io-uring, kvm, linux-arm-kernel, linux-crypto, linux-ide, linux-iommu, linux-kselftest, linux-mips, linux-mm, linux-mmc, linux-riscv, linux-s390, linux-scsi, lkml, virtualization
On Thu, Aug 28, 2025 at 12:01:23AM +0200, David Hildenbrand wrote:
Within a folio/compound page, nth_page() is no longer required. Given that we call folio_test_partial_kmap()+kmap_local_page(), the code would already be problematic if the pages would span multiple folios. So let's just assume that all src pages belong to a single folio/compound page and can be iterated ordinarily. The dst page is currently always a single page, so we're not actually iterating anything. Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Hildenbrand <redacted>
On basis of src pages being within the same folio, LGTM, so: Reviewed-by: Lorenzo Stoakes <redacted>
quoted hunk ↗ jump to hunk
--- io_uring/zcrx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index e5ff49f3425e0..18c12f4b56b6c 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c@@ -975,9 +975,9 @@ static ssize_t io_copy_page(struct io_copy_cache *cc, struct page *src_page, if (folio_test_partial_kmap(page_folio(dst_page)) || folio_test_partial_kmap(page_folio(src_page))) { - dst_page = nth_page(dst_page, dst_offset / PAGE_SIZE); + dst_page += dst_offset / PAGE_SIZE; dst_offset = offset_in_page(dst_offset); - src_page = nth_page(src_page, src_offset / PAGE_SIZE); + src_page += src_offset / PAGE_SIZE; src_offset = offset_in_page(src_offset); n = min(PAGE_SIZE - src_offset, PAGE_SIZE - dst_offset); n = min(n, len); --2.50.1