From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 00DC81547CC for ; Tue, 3 Jun 2025 06:05:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748930703; cv=none; b=seDqlJF70TAFY+GGLYGMlOBx8MktP1GHL43zw6Y9WUEcBVJRzChbU2jjJQP3o/gmvBHllf7tOR78hnE6d4g0d4eNgw2ZY1BYOiZ9YyiKqAU64m4Wea8xRP9+vB62a0AmPe92WaPWuVLM4k+CgZ6hVugWNSPn8kHc0SpP7U7rT3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748930703; c=relaxed/simple; bh=nafkrpSQlbwAWZTQXHdO/XS10PSgYdUEAo0Xdz9PIVc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hFPiIDobmaV3nog/JMYgJyH4i4FIuVbiJ/Ji6THuTUJtYv0ypS7jMrvo9ny0VpIcq1cFVGqHih6Lg6i2j1/jVx2Zhiucf63z0EnroNT87PhbCo+Jaix2zVvqqF5/N11/qOYzKIr/fr203qX/VdY+85t1wr80dZlCQ/njWw1nBa8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0486212FC; Mon, 2 Jun 2025 23:04:38 -0700 (PDT) Received: from [10.164.18.47] (a077893.blr.arm.com [10.164.18.47]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A60313F673; Mon, 2 Jun 2025 23:04:50 -0700 (PDT) Message-ID: Date: Tue, 3 Jun 2025 11:34:46 +0530 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 RFC] mm: madvise: use walk_page_range_vma() for madvise_free_single_vma() To: Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Barry Song , "Liam R. Howlett" , Lorenzo Stoakes , David Hildenbrand , Vlastimil Babka , Jann Horn , Suren Baghdasaryan , Lokesh Gidra , Tangquan Zheng References: <20250603013154.5905-1-21cnbao@gmail.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250603013154.5905-1-21cnbao@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/3/25 07:01, Barry Song wrote: > From: Barry Song > > We've already found the VMA before calling madvise_free_single_vma(), > so calling walk_page_range() and doing find_vma() again seems > unnecessary. It also prevents potential optimizations for MADV_FREE > to use a per-VMA lock. > > Cc: "Liam R. Howlett" > Cc: Lorenzo Stoakes > Cc: David Hildenbrand > Cc: Vlastimil Babka > Cc: Jann Horn > Cc: Suren Baghdasaryan > Cc: Lokesh Gidra > Cc: Tangquan Zheng > Signed-off-by: Barry Song > --- > mm/madvise.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/madvise.c b/mm/madvise.c > index d408ffa404b3..c6a28a2d3ff8 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -826,7 +826,7 @@ static int madvise_free_single_vma(struct madvise_behavior *madv_behavior, > > mmu_notifier_invalidate_range_start(&range); > tlb_start_vma(tlb, vma); > - walk_page_range(vma->vm_mm, range.start, range.end, > + walk_page_range_vma(vma, range.start, range.end, > &madvise_free_walk_ops, tlb); > tlb_end_vma(tlb, vma); > mmu_notifier_invalidate_range_end(&range); This indeed looks like an improvement dropping a redundant VMA look up and also opening up potential optimization later using per-VMA lock. Reviewed-by: Anshuman Khandual