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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6819CAC58E for ; Mon, 15 Sep 2025 04:24:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EE3FB8E0003; Mon, 15 Sep 2025 00:24:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E94948E0001; Mon, 15 Sep 2025 00:24:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA9E18E0003; Mon, 15 Sep 2025 00:24:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id C94348E0001 for ; Mon, 15 Sep 2025 00:24:49 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 6C5551A03CD for ; Mon, 15 Sep 2025 04:24:49 +0000 (UTC) X-FDA: 83890193898.28.AB2B282 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) by imf08.hostedemail.com (Postfix) with ESMTP id F36A7160003 for ; Mon, 15 Sep 2025 04:24:46 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=uER8sLex; spf=pass (imf08.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.170 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757910287; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ehnEhT9IwpoRpyq7W3B9rNarRzhELO0M7YbeeCPAQMM=; b=TEV1gfJ6sc44AGeHlV5UzYDS22X5n6IYd0QI3lFFsEXS9noDTQvMWY9JGKGQq67blrqpM7 TMd109RURZ5g/fMdg2b7nj8MJ3UKWJzqv+gzuYU7SV5Xqvw2SPWe2GT7crv5xz7o27Ov4W t1W44fi7otyTJt3bnDrMP4e3ikU697w= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=uER8sLex; spf=pass (imf08.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.170 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757910287; a=rsa-sha256; cv=none; b=6PAWFPCjM1QMJl673q5vNHWrryyEVGSATpZZmTZcoeIVmj4TtMtbTFM9atc3/QHADs1XoK aIpWqx1MtlkmNiWmUINPrtfan8EN+loph76gZo117eiKziDkDVCKiz6bTk1C8/lgabHbtB DIRNd0NWXIrkWHznrZqzcPU/MDDyKrk= Message-ID: <434ecc5a-3aec-4381-8477-8a7d09220051@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1757910284; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ehnEhT9IwpoRpyq7W3B9rNarRzhELO0M7YbeeCPAQMM=; b=uER8sLexksdHO9XbHYOptdkH/NAAPFYOzOUJVgerwDt80blqcBLHvrqWNDz7+G4w8LzTlA GC+tt+uJ0Ivobr6/GHjNDSAKDmfu6l3H7x9psd+Z+emAk+uqhUL/8aSBrVIEJqT0MZ1zCL nTBGcgAtpfaGLLHgFP2UZ8NknmN9Jyk= Date: Mon, 15 Sep 2025 12:24:19 +0800 MIME-Version: 1.0 Subject: Re: [PATCH mm-new 2/3] mm: clean up and expose is_guard_pte_marker() Content-Language: en-US To: Dev Jain Cc: ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, baohua@kernel.org, ioworker0@gmail.com, lorenzo.stoakes@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Kairui Song , akpm@linux-foundation.org, david@redhat.com References: <20250914143547.27687-1-lance.yang@linux.dev> <20250914143547.27687-3-lance.yang@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: F36A7160003 X-Stat-Signature: goyx47rn5m61wybhfw7e5xg1qwhnp6hp X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1757910286-204627 X-HE-Meta: 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 H9TvHqDj OzrWnh9fOOUjLBZlDvrel6bPeyGK1Cz0i2I7QQKx8YzGJ09sBoLZtkKjb8YQc65ixuRQFhnD0tfLJ0XttccoX84y1BqwcmN6J0Mz+1FP41ChiMXg+mtuXWdsmuWS/BqsHP3v93D3DU0TFKOTIkiwfzKnoa4ibjNZ5t+JArUZiCZHvFtoWha3nESXgtSlTatTcfwMTsVf2mXBputCA2QnLAL7fn9qo+jtJF1HBW4qH2RHItkpKEtqU+VkWgnYbDkn5IImPy+jpsUs2AV8HfMg/dfGGXhIc2A0+L5u7v0I5C7jegxhyVlETBbnNhVXVDrPMI3M2OBueCrgmLrUfI26BXERSvQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2025/9/15 00:38, Dev Jain wrote: > > On 14/09/25 8:05 pm, Lance Yang wrote: >> From: Lance Yang >> >> is_guard_pte_marker() performs a redundant check because it calls both >> is_pte_marker() and is_guard_swp_entry(), both of which internally check >> for a PTE marker. >> >> is_guard_pte_marker() >>   |- is_pte_marker() >>   |   `- is_pte_marker_entry()  // First check >>   `- is_guard_swp_entry() >>       `- is_pte_marker_entry()  // Second, redundant check >> >> While a modern compiler could likely optimize this away, let's have clean >> code and not rely on it ;) >> >> Also, make it available for hugepage collapsing code. > > The movement of the code should be merged with the next patch. Thanks for the suggestion ;) I'd prefer to keep them as separate patches to make them easier to review, if that's okay. Cheers, Lance > >> >> Cc: Kairui Song >> Signed-off-by: Lance Yang >> --- >>   include/linux/swapops.h | 6 ++++++ >>   mm/madvise.c            | 6 ------ >>   2 files changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/include/linux/swapops.h b/include/linux/swapops.h >> index 59c5889a4d54..7f5684fa043b 100644 >> --- a/include/linux/swapops.h >> +++ b/include/linux/swapops.h >> @@ -469,6 +469,12 @@ static inline int is_guard_swp_entry(swp_entry_t >> entry) >>           (pte_marker_get(entry) & PTE_MARKER_GUARD); >>   } >> +static inline bool is_guard_pte_marker(pte_t ptent) >> +{ >> +    return is_swap_pte(ptent) && >> +           is_guard_swp_entry(pte_to_swp_entry(ptent)); >> +} >> + >>   /* >>    * This is a special version to check pte_none() just to cover the >> case when >>    * the pte is a pte marker.  It existed because in many cases the >> pte marker >> diff --git a/mm/madvise.c b/mm/madvise.c >> index 35ed4ab0d7c5..bd46e6788fac 100644 >> --- a/mm/madvise.c >> +++ b/mm/madvise.c >> @@ -1069,12 +1069,6 @@ static bool is_valid_guard_vma(struct >> vm_area_struct *vma, bool allow_locked) >>       return !(vma->vm_flags & disallowed); >>   } >> -static bool is_guard_pte_marker(pte_t ptent) >> -{ >> -    return is_pte_marker(ptent) && >> -        is_guard_swp_entry(pte_to_swp_entry(ptent)); >> -} >> - >>   static int guard_install_pud_entry(pud_t *pud, unsigned long addr, >>                      unsigned long next, struct mm_walk *walk) >>   {