From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C47A28E2 for ; Mon, 20 Jun 2022 17:27:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48CB1C3411B; Mon, 20 Jun 2022 17:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655746070; bh=G5GtmLDra6Mj3BFy+b9Vvm7SvXbbbJSxaIQXBk1cDAA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L+EiA5KkFCe1Sr4egatDOyVsNe3RL7c+F91ZXFwhvRjmLyif12dAtV8wozFeolfw6 pdvqIMIhuN3NQaLBGskji+x9/JP9kTFmCJgFm1NovISDvUlpnMJVO0e8hRiS56CG95 fv3kgo8fmdjlWLNJlHwdQRWE2YZG1emH0kCvivButPjGoxTslZk8azvrOfkbZrLvEC iL/NiILWy0zfSNJhhRUNQ9sSocCTbADvJVC4tIEUoweGOe5LEyPOC9efCqg4G93cWk hMNhuJojWmMvN8QObiUlkGM9WGtr+NHfPLi/m1G2GrwrVnlNMdjqrLu3vcLHTgEjLK 5ITAO/4gGhkbw== From: SeongJae Park To: Baolin Wang Cc: sj@kernel.org, akpm@linux-foundation.org, mike.kravetz@oracle.com, songmuchun@bytedance.com, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] mm/damon: Use set_huge_pte_at() to make huge pte old Date: Mon, 20 Jun 2022 17:27:42 +0000 Message-Id: <20220620172742.48766-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <1655692482-28797-1-git-send-email-baolin.wang@linux.alibaba.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Baolin, On Mon, 20 Jun 2022 10:34:42 +0800 Baolin Wang wrote: > The huge_ptep_set_access_flags() can not make the huge pte old according > to the discussion [1], that means we will always mornitor the young state > of the hugetlb though we stopped accessing the hugetlb, as a result DAMON > will get inaccurate accessing statistics. > > So changing to use set_huge_pte_at() to make the huge pte old to fix this > issue. > > [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ > > Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") As the commit has merged in from v5.17, I guess it would be better to do below? Cc: > Signed-off-by: Baolin Wang Other than that, Reviewed-by: SeongJae Park Thanks, SJ > --- > mm/damon/vaddr.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 5767be72c181..d24148a8149f 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -337,8 +337,7 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm, > if (pte_young(entry)) { > referenced = true; > entry = pte_mkold(entry); > - huge_ptep_set_access_flags(vma, addr, pte, entry, > - vma->vm_flags & VM_WRITE); > + set_huge_pte_at(mm, addr, pte, entry); > } > > #ifdef CONFIG_MMU_NOTIFIER > -- > 2.27.0