From patchwork Wed Sep 13 16:56:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13383579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8F6CEE01E0 for ; Wed, 13 Sep 2023 16:57:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230298AbjIMQ57 (ORCPT ); Wed, 13 Sep 2023 12:57:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229973AbjIMQ5y (ORCPT ); Wed, 13 Sep 2023 12:57:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A650D1BC3 for ; Wed, 13 Sep 2023 09:57:03 -0700 (PDT) DKIM-Signature: v=1; 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Wed, 13 Sep 2023 16:56:55 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D05340C6EA8; Wed, 13 Sep 2023 16:56:54 +0000 (UTC) From: David Howells To: Al Viro , Linus Torvalds Cc: David Howells , Jens Axboe , Christoph Hellwig , Christian Brauner , David Laight , Matthew Wilcox , Jeff Layton , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 01/13] iov_iter: Add a benchmarking kunit test Date: Wed, 13 Sep 2023 17:56:36 +0100 Message-ID: <20230913165648.2570623-2-dhowells@redhat.com> In-Reply-To: <20230913165648.2570623-1-dhowells@redhat.com> References: <20230913165648.2570623-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org --- lib/kunit_iov_iter.c | 181 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 181 insertions(+) diff --git a/lib/kunit_iov_iter.c b/lib/kunit_iov_iter.c index 859b67c4d697..478fea956f58 100644 --- a/lib/kunit_iov_iter.c +++ b/lib/kunit_iov_iter.c @@ -756,6 +756,184 @@ static void __init iov_kunit_extract_pages_xarray(struct kunit *test) KUNIT_SUCCEED(); } +static void iov_kunit_free_page(void *data) +{ + __free_page(data); +} + +static void __init iov_kunit_benchmark_print_stats(struct kunit *test, + unsigned int *samples) +{ + unsigned long total = 0; + int i; + + for (i = 0; i < 16; i++) { + total += samples[i]; + kunit_info(test, "run %x: %u uS\n", i, samples[i]); + } + + kunit_info(test, "avg %lu uS\n", total / 16); +} + +/* + * Time copying 256MiB through an ITER_BVEC. + */ +static void __init iov_kunit_benchmark_bvec(struct kunit *test) +{ + struct iov_iter iter; + struct bio_vec *bvec; + struct page *page, **pages; + unsigned int samples[16]; + ktime_t a, b; + ssize_t copied; + size_t size = 256 * 1024 * 1024, npages = size / PAGE_SIZE; + void *scratch; + int i; + + /* Allocate a page and tile it repeatedly in the buffer. */ + page = alloc_page(GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, page); + kunit_add_action_or_reset(test, iov_kunit_free_page, page); + + bvec = kunit_kmalloc_array(test, npages, sizeof(bvec[0]), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, bvec); + for (i = 0; i < npages; i++) + bvec_set_page(&bvec[i], page, PAGE_SIZE, 0); + + /* Create a single large buffer to copy to/from. */ + pages = kunit_kmalloc_array(test, npages, sizeof(pages[0]), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, pages); + for (i = 0; i < npages; i++) + pages[i] = page; + + scratch = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, scratch); + kunit_add_action_or_reset(test, iov_kunit_unmap, scratch); + + /* Perform and time a bunch of copies. */ + kunit_info(test, "Benchmarking copy_to_iter() over BVEC:\n"); + for (i = 0; i < 16; i++) { + iov_iter_bvec(&iter, ITER_DEST, bvec, npages, size); + a = ktime_get_real(); + copied = copy_to_iter(scratch, size, &iter); + b = ktime_get_real(); + KUNIT_EXPECT_EQ(test, copied, size); + samples[i] = ktime_to_us(ktime_sub(b, a)); + } + + iov_kunit_benchmark_print_stats(test, samples); + KUNIT_SUCCEED(); +} + +/* + * Time copying 256MiB through an ITER_BVEC in 256 page chunks. + */ +static void __init iov_kunit_benchmark_bvec_split(struct kunit *test) +{ + struct iov_iter iter; + struct bio_vec *bvec; + struct page *page, **pages; + unsigned int samples[16]; + ktime_t a, b; + ssize_t copied; + size_t size, npages = 64; + void *scratch; + int i, j; + + /* Allocate a page and tile it repeatedly in the buffer. */ + page = alloc_page(GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, page); + kunit_add_action_or_reset(test, iov_kunit_free_page, page); + + /* Create a single large buffer to copy to/from. */ + pages = kunit_kmalloc_array(test, npages, sizeof(pages[0]), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, pages); + for (i = 0; i < npages; i++) + pages[i] = page; + + scratch = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, scratch); + kunit_add_action_or_reset(test, iov_kunit_unmap, scratch); + + /* Perform and time a bunch of copies. */ + kunit_info(test, "Benchmarking copy_to_iter() over BVEC:\n"); + for (i = 0; i < 16; i++) { + size = 256 * 1024 * 1024; + a = ktime_get_real(); + do { + size_t part = min(size, npages * PAGE_SIZE); + + bvec = kunit_kmalloc_array(test, npages, sizeof(bvec[0]), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, bvec); + for (j = 0; j < npages; j++) + bvec_set_page(&bvec[j], page, PAGE_SIZE, 0); + + iov_iter_bvec(&iter, ITER_DEST, bvec, npages, part); + copied = copy_to_iter(scratch, part, &iter); + KUNIT_EXPECT_EQ(test, copied, part); + size -= part; + } while (size > 0); + b = ktime_get_real(); + samples[i] = ktime_to_us(ktime_sub(b, a)); + } + + iov_kunit_benchmark_print_stats(test, samples); + KUNIT_SUCCEED(); +} + +/* + * Time copying 256MiB through an ITER_XARRAY. + */ +static void __init iov_kunit_benchmark_xarray(struct kunit *test) +{ + struct iov_iter iter; + struct xarray *xarray; + struct page *page, **pages; + unsigned int samples[16]; + ktime_t a, b; + ssize_t copied; + size_t size = 256 * 1024 * 1024, npages = size / PAGE_SIZE; + void *scratch; + int i; + + /* Allocate a page and tile it repeatedly in the buffer. */ + page = alloc_page(GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, page); + kunit_add_action_or_reset(test, iov_kunit_free_page, page); + + xarray = iov_kunit_create_xarray(test); + + for (i = 0; i < npages; i++) { + void *x = xa_store(xarray, i, page, GFP_KERNEL); + + KUNIT_ASSERT_FALSE(test, xa_is_err(x)); + } + + /* Create a single large buffer to copy to/from. */ + pages = kunit_kmalloc_array(test, npages, sizeof(pages[0]), GFP_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, pages); + for (i = 0; i < npages; i++) + pages[i] = page; + + scratch = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL); + KUNIT_ASSERT_NOT_NULL(test, scratch); + kunit_add_action_or_reset(test, iov_kunit_unmap, scratch); + + /* Perform and time a bunch of copies. */ + kunit_info(test, "Benchmarking copy_to_iter() over XARRAY:\n"); + for (i = 0; i < 16; i++) { + iov_iter_xarray(&iter, ITER_DEST, xarray, 0, size); + a = ktime_get_real(); + copied = copy_to_iter(scratch, size, &iter); + b = ktime_get_real(); + KUNIT_EXPECT_EQ(test, copied, size); + samples[i] = ktime_to_us(ktime_sub(b, a)); + } + + iov_kunit_benchmark_print_stats(test, samples); + KUNIT_SUCCEED(); +} + static struct kunit_case __refdata iov_kunit_cases[] = { KUNIT_CASE(iov_kunit_copy_to_kvec), KUNIT_CASE(iov_kunit_copy_from_kvec), @@ -766,6 +944,9 @@ static struct kunit_case __refdata iov_kunit_cases[] = { KUNIT_CASE(iov_kunit_extract_pages_kvec), KUNIT_CASE(iov_kunit_extract_pages_bvec), KUNIT_CASE(iov_kunit_extract_pages_xarray), + KUNIT_CASE(iov_kunit_benchmark_bvec), + KUNIT_CASE(iov_kunit_benchmark_bvec_split), + KUNIT_CASE(iov_kunit_benchmark_xarray), {} };