From mboxrd@z Thu Jan 1 00:00:00 1970 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 EB3FDC4332F for ; Tue, 14 Nov 2023 16:06:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233781AbjKNQGi (ORCPT ); Tue, 14 Nov 2023 11:06:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229507AbjKNQGg (ORCPT ); Tue, 14 Nov 2023 11:06:36 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E7CF3FE for ; Tue, 14 Nov 2023 08:06:32 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B5E59C15; Tue, 14 Nov 2023 08:07:17 -0800 (PST) Received: from [10.1.27.144] (XHFQ2J9959.cambridge.arm.com [10.1.27.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F319E3F641; Tue, 14 Nov 2023 08:06:31 -0800 (PST) Message-ID: <696a0a99-eb42-4e13-be14-58a88c9c33f7@arm.com> Date: Tue, 14 Nov 2023 16:06:30 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] selftests/mm: check that PAGEMAP_SCAN returns correct categories Content-Language: en-GB To: Andrei Vagin , Andrew Morton , Muhammad Usama Anjum Cc: linux-kernel@vger.kernel.org References: <20231106220959.296568-1-avagin@google.com> <20231106220959.296568-2-avagin@google.com> From: Ryan Roberts In-Reply-To: <20231106220959.296568-2-avagin@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/11/2023 22:09, Andrei Vagin wrote: > Right now, tests read page flags from /proc/pid/pagemap files. With this > change, tests will check that PAGEMAP_SCAN return correct information > too. > > Signed-off-by: Andrei Vagin > --- > tools/testing/selftests/mm/vm_util.c | 53 ++++++++++++++++++++++++++-- > 1 file changed, 50 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c > index 3082b40492dd..ec3478b96e4c 100644 > --- a/tools/testing/selftests/mm/vm_util.c > +++ b/tools/testing/selftests/mm/vm_util.c > @@ -4,6 +4,7 @@ > #include > #include > #include > +#include > #include > #include > #include "../kselftest.h" > @@ -28,19 +29,65 @@ uint64_t pagemap_get_entry(int fd, char *start) > return entry; > } > > +static uint64_t pagemap_scan_get_categories(int fd, char *start) > +{ > + struct pm_scan_arg arg; > + struct page_region r; > + long ret; > + > + arg.start = (uintptr_t)start; > + arg.end = (uintptr_t)(start + psize()); > + arg.vec = (uintptr_t)&r; > + arg.vec_len = 1; > + arg.flags = 0; > + arg.size = sizeof(struct pm_scan_arg); > + arg.max_pages = 0; > + arg.category_inverted = 0; > + arg.category_mask = 0; > + arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE | > + PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO | > + PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY; > + arg.return_mask = arg.category_anyof_mask; > + > + ret = ioctl(fd, PAGEMAP_SCAN, &arg); > + if (ret < 0) > + ksft_exit_fail_msg("PAGEMAP_SCAN failed: %s\n", strerror(errno)); FYI, when run against kernel v6.7-rc1, this fails with EINVAL. I'm guessing you've added this as part of testing an extension to this ABI and its only present in mm-unstable? I believe that normally we try to keep selftests backwards compatible so they run on older kernels (a feature I rely on). As a result 3 or so test suites are immediately failing (inc cow). Can this be fixed to fallback to old behaviour gracefully in this case? Thanks, Ryan > + if (ret == 0) > + return 0; > + return r.categories; > +} > + > +static bool page_entry_is(int fd, char *start, char *desc, > + uint64_t pagemap_flags, uint64_t pagescan_flags) > +{ > + bool m, s; > + > + m = pagemap_get_entry(fd, start) & pagemap_flags; > + s = pagemap_scan_get_categories(fd, start) & pagescan_flags; > + if (m == s) > + return m; > + > + ksft_exit_fail_msg( > + "read and ioctl return unmatched results for %s: %d %d", desc, m, s); > + return m; > +} > + > bool pagemap_is_softdirty(int fd, char *start) > { > - return pagemap_get_entry(fd, start) & PM_SOFT_DIRTY; > + return page_entry_is(fd, start, "soft-dirty", > + PM_SOFT_DIRTY, PAGE_IS_SOFT_DIRTY); > } > > bool pagemap_is_swapped(int fd, char *start) > { > - return pagemap_get_entry(fd, start) & PM_SWAP; > + return page_entry_is(fd, start, "swap", PM_SWAP, PAGE_IS_SWAPPED); > } > > bool pagemap_is_populated(int fd, char *start) > { > - return pagemap_get_entry(fd, start) & (PM_PRESENT | PM_SWAP); > + return page_entry_is(fd, start, "populated", > + PM_PRESENT | PM_SWAP, > + PAGE_IS_PRESENT | PAGE_IS_SWAPPED); > } > > unsigned long pagemap_get_pfn(int fd, char *start)