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 7A7133D331A; Mon, 4 May 2026 12:43:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777898580; cv=none; b=CgdBv0Mas/7x+XlNME7ppqsh/jD9gMOuNoT/fujOpn7OZx/lbuoQKqYpXKkMOwmzebBGS4attPkIXwRf6ZiLvc4VpaM2Ij3awK8rf/pXSaDkiIvhkZRoVhmcymEz6zBYyPSwRriLt+HeU248KSmLieSL1SsFiTUoN+ABDJ+9qjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777898580; c=relaxed/simple; bh=NzJpitNc5KGF5edt7ROkeENHHPy+fXwPIFhAtjW/MgU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mC50htNoQlHIDn9GBYaxxqzGfN77MZTGL40R4ZUXuDrsxqXYCEiGZiWlsXgE79+fO608Y9xbvDBeVHUz32NfCa73ZppqdvGDKYHtgIebI4dbP3lZl3zcMgYx/dJ2tZRZF/kCZkP4Llffgd/YXOI5qWjFeq/kZC2o97KlwfE63rQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U4BfRak+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U4BfRak+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43410C2BCB8; Mon, 4 May 2026 12:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777898580; bh=NzJpitNc5KGF5edt7ROkeENHHPy+fXwPIFhAtjW/MgU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=U4BfRak+eY+i5BA5861mvdadrgM5u48QQjyvKkvwnkwYxc/1luf9PBb3UpziT2lGE ts2LeuvkHo2thOkEcDVSGhHJ/MFI23QbVYiIPdDt8q05wQ115ml4ZLbaep4tk1wk6E wJPuT0jxyYGdSEXxdEyxPdpY2UJn1eVrDg3ZRbwHpDgdmrV6d0i9FvrYD4cgglI3zq acf3AAIXgVRxdFTUgaX57XIclTlMPjd7kYButfEDXi5FOoPSA6rZNJfcqWQ9ankozS 6o0fzZyg+cpvTQHfiKk5dyw5VAJzBU+rTv7fXQyI04YKWPz/9qSdHmjUTARqVVr3ga wtSKQNssoj3Dw== Message-ID: <40ab8829-5f70-4474-9cf5-2c8da96d56d6@kernel.org> Date: Mon, 4 May 2026 14:42:55 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/page_vma_mapped_walk: add missing pgtable entry accessors To: Alexander Gordeev Cc: Andrew Morton , Lorenzo Stoakes , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , linux-s390@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260427052000.196402-1-agordeev@linux.ibm.com> <69c4c12c-7cdc-4a17-9eb7-6fb1a61f9834@kernel.org> <109bc59e-1308-4505-b8c6-3376aed74585@kernel.org> <20260503065113.3385165A37-agordeev@linux.ibm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/3/26 08:51, Alexander Gordeev wrote: > On Fri, May 01, 2026 at 09:01:09PM +0200, David Hildenbrand (Arm) wrote: >> On 4/29/26 15:47, Alexander Gordeev wrote: >>> >>> (*) >>> >>> >>> Ok, that is a different topic. I actually tried to resolve the lockless >>> issue(s) in (*) while the direct dereferences just seemed to be relevant >>> to go along (similarly to the GUP patch). >>> >>> But I would rather resend ptep_get() => ptep_get_lockless() fixes for >>> this patch. >>> >>> Would it work? >> >> You mean only sending {*) ? > > Only this: > > diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c > index a4d52fdb3056..6559e17f11c2 100644 > --- a/mm/page_vma_mapped.c > +++ b/mm/page_vma_mapped.c > @@ -41,7 +41,7 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp, > if (!pvmw->pte) > return false; > > - ptent = ptep_get(pvmw->pte); > + ptent = ptep_get_lockless(pvmw->pte); > > if (pte_none(ptent)) { > return false; > @@ -310,7 +310,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) > goto restart; > } > pvmw->pte++; > - } while (pte_none(ptep_get(pvmw->pte))); > + } while (pte_none(ptep_get_lockless(pvmw->pte))); > Makes sense! -- Cheers, David