From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gabriel Krisman Bertazi Subject: Re: [PATCH V3] selftests: vm: Add test for Soft-Dirty PTE bit References: <20220224212335.3045905-1-usama.anjum@collabora.com> <3b7c068b-ac7e-62fc-f0cd-a8dbf8642876@redhat.com> <6133317f-4da0-3aae-f352-b75f0f94dbd4@linuxfoundation.org> <87o82mkhif.fsf@collabora.com> Date: Fri, 04 Mar 2022 11:14:08 -0500 In-Reply-To: (Shuah Khan's message of "Thu, 3 Mar 2022 14:46:08 -0700") Message-ID: <87r17hg0fj.fsf@collabora.com> MIME-Version: 1.0 Content-Type: text/plain List-ID: To: Shuah Khan Cc: David Hildenbrand , Muhammad Usama Anjum , Andrew Morton , Shuah Khan , kernel@collabora.com, kernelci@groups.io, Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Shuah Khan writes: > On 3/3/22 11:39 AM, Gabriel Krisman Bertazi wrote: >> Shuah Khan writes: >> >>> On 2/28/22 2:37 AM, David Hildenbrand wrote: >>>> On 24.02.22 22:23, Muhammad Usama Anjum wrote: >>>>> This introduces three tests: >>>>> 1) Sanity check soft dirty basic semantics: allocate area, clean, dirty, >>>>> check if the SD bit flipped. >>>>> 2) Check VMA reuse: validate the VM_SOFTDIRTY usage >>>>> 3) Check soft-dirty on huge pages >>>>> >>>>> This was motivated by Will Deacon's fix commit 912efa17e512 ("mm: proc: >>>>> Invalidate TLB after clearing soft-dirty page state"). I was tracking the >>>>> same issue that he fixed, and this test would have caught it. >>>>> >>>> A note that madv_populate.c already contains some SOFTDIRTY tests >>>> regarding MADV_POPULATE. Eventually we want to factor out >>>> softdirty/pagemap handling+checks for easier reuse. >>>> >>> >>> Is this patch unnecessary then? >> It is not unnecessary since the madv test doesn't cover the bug tested >> here, afaik. But, as mentioned when I originally submitted this patch, >> it should be merged into selftests/vm/madv_populate.c or, at least, >> reuse that existing infrastructure. >> https://lore.kernel.org/lkml/87lf553z5g.fsf@collabora.com/ >> > > Oops this one came in a few months ago and appears to have slipped > through and didn't get the right attention. Sorry about that. > > Please resend the patch and cc all the everybody on this thread. > > I would like to have your patch reviewed and looked at first. This > patch needs rework sine it has several comments to be addressed. Hi Shuah, The patch being discussed in that thread is the same that Usama is proposing here, minus a few modifications. Usama has taken over the work to upstream it. We just spoke, and he will follow up with a new version that addresses the coding issues and reuses the infrastructure from madv_populate.c Sorry for the noise. -- Gabriel Krisman Bertazi