From patchwork Tue Aug 1 12:48:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13336693 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 A2092C001DF for ; Tue, 1 Aug 2023 12:50:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232535AbjHAMua (ORCPT ); Tue, 1 Aug 2023 08:50:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233820AbjHAMuQ (ORCPT ); Tue, 1 Aug 2023 08:50:16 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC56D210A for ; Tue, 1 Aug 2023 05:49:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690894164; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ETNtty+qD9MfEou6PkXGN63LTSt4s/cNeotNKd9s/vU=; b=Y6+Y8HQSblAUsq/kZUZdH0L27TvMnjLZRAC03d+wrNuf0z2BRiXaVunM6QlOd6VCQWGUZZ KumUFKt5m/uAtSsEaFxYR/jSf+NKUs0ACzaclfcpygTQck3/HWJTayWjR8Eldmeb9ovqz+ WV7ahOrY+dqnxeK7bW9tWqYjnJtQqu8= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-613-KCGrX7soNoWrUz7xASwZ2A-1; Tue, 01 Aug 2023 08:49:20 -0400 X-MC-Unique: KCGrX7soNoWrUz7xASwZ2A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0FC5529ABA07; Tue, 1 Aug 2023 12:49:20 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.193.232]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0D58AC585A0; Tue, 1 Aug 2023 12:49:16 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, David Hildenbrand , Andrew Morton , Linus Torvalds , liubo , Peter Xu , Matthew Wilcox , Hugh Dickins , Jason Gunthorpe , John Hubbard , Mel Gorman , Shuah Khan , Paolo Bonzini Subject: [PATCH v2 6/8] mm/huge_memory: remove stale NUMA hinting comment from follow_trans_huge_pmd() Date: Tue, 1 Aug 2023 14:48:42 +0200 Message-ID: <20230801124844.278698-7-david@redhat.com> In-Reply-To: <20230801124844.278698-1-david@redhat.com> References: <20230801124844.278698-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org That comment for pmd_protnone() was added in commit 2b4847e73004 ("mm: numa: serialise parallel get_user_page against THP migration"), which noted: THP does not unmap pages due to a lack of support for migration entries at a PMD level. This allows races with get_user_pages Nowadays, we do have PMD migration entries, so the comment no longer applies. Let's drop it. Signed-off-by: David Hildenbrand Acked-by: Mel Gorman --- mm/huge_memory.c | 1 - 1 file changed, 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2cd3e5502180..0b709d2c46c6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1467,7 +1467,6 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd)) return ERR_PTR(-EFAULT); - /* Full NUMA hinting faults to serialise migration in fault paths */ if (pmd_protnone(*pmd) && !gup_can_follow_protnone(vma, flags)) return NULL;