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 51D3D3032A for ; Mon, 1 Jul 2024 07:55:20 +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=1719820524; cv=none; b=ZUzX4S98nmh8FKhwCa/01z1EwCuFVzMZM1a3Y9A2zi2bc2DFTeJJHp6fzLwZuATO79/7NVgQbSWLoeKlt6fJCNv11fMEcgslrIz8GY/l9zYUiOBKFjUGSbRXjuC6Irizrmqt//psSjL/ps0v8VFdQTBvcAyMlLXhr9Vxj85lLng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719820524; c=relaxed/simple; bh=gay1RgPq+0OMvJZCVvDOeD0M6k0/1vWr3ns0cLsv40s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ouYF6E3LdSgMKwdwpSYSykuQypEoiJIfWWXV2G+8Sn6go9Xu7Tmlf0Q3YxSf9mFG+BjGe80/3lCmRJ/DPMp92L8KQACaKD7HjRSzndk8/QMZwzhNMaQMmgNKDUuZ7N8C5pqCazydvCHHYlF4bYOx1++/HWYjD77u/7hoPG+1P4M= 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 08F61339; Mon, 1 Jul 2024 00:55:39 -0700 (PDT) Received: from [10.57.72.41] (unknown [10.57.72.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A0E473F766; Mon, 1 Jul 2024 00:55:12 -0700 (PDT) Message-ID: <4b38db15-0716-4ffb-a38b-bd6250eb93da@arm.com> Date: Mon, 1 Jul 2024 08:55:11 +0100 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] support "THPeligible" semantics for mTHP with anonymous shmem Content-Language: en-GB To: Bang Li , hughd@google.com, akpm@linux-foundation.org Cc: david@redhat.com, wangkefeng.wang@huawei.com, baolin.wang@linux.alibaba.com, ziy@nvidia.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20240628104926.34209-1-libang.li@antgroup.com> From: Ryan Roberts In-Reply-To: <20240628104926.34209-1-libang.li@antgroup.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 28/06/2024 11:49, Bang Li wrote: > After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for > anonymous shmem"), we can configure different policies through > the multi-size THP sysfs interface for anonymous shmem. But > currently "THPeligible" indicates only whether the mapping is > eligible for allocating THP-pages as well as the THP is PMD > mappable or not for anonymous shmem, we need to support semantics > for mTHP with anonymous shmem similar to those for mTHP with > anonymous memory. > > Signed-off-by: Bang Li > --- > fs/proc/task_mmu.c | 10 +++++++--- > include/linux/huge_mm.h | 11 +++++++++++ > mm/shmem.c | 9 +-------- > 3 files changed, 19 insertions(+), 11 deletions(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 93fb2c61b154..09b5db356886 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -870,6 +870,7 @@ static int show_smap(struct seq_file *m, void *v) > { > struct vm_area_struct *vma = v; > struct mem_size_stats mss = {}; > + bool thp_eligible; > > smap_gather_stats(vma, &mss, 0); > > @@ -882,9 +883,12 @@ static int show_smap(struct seq_file *m, void *v) > > __show_smap(m, &mss, false); > > - seq_printf(m, "THPeligible: %8u\n", > - !!thp_vma_allowable_orders(vma, vma->vm_flags, > - TVA_SMAPS | TVA_ENFORCE_SYSFS, THP_ORDERS_ALL)); > + thp_eligible = !!thp_vma_allowable_orders(vma, vma->vm_flags, > + TVA_SMAPS | TVA_ENFORCE_SYSFS, THP_ORDERS_ALL); > + if (vma_is_anon_shmem(vma)) > + thp_eligible = !!shmem_allowable_huge_orders(file_inode(vma->vm_file), > + vma, vma->vm_pgoff, thp_eligible); Afraid I haven't been following the shmem mTHP support work as much as I would have liked, but is there a reason why we need a separate function for shmem? Couldn't (shouldn't) thp_vma_allowable_orders() be taught to handle shmem too? > + seq_printf(m, "THPeligible: %8u\n", thp_eligible); > > if (arch_pkeys_enabled()) > seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 212cca384d7e..f87136f38aa1 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -267,6 +267,10 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma, > return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders); > } > > +unsigned long shmem_allowable_huge_orders(struct inode *inode, > + struct vm_area_struct *vma, pgoff_t index, > + bool global_huge); > + > struct thpsize { > struct kobject kobj; > struct list_head node; > @@ -460,6 +464,13 @@ static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma, > return 0; > } > > +static inline unsigned long shmem_allowable_huge_orders(struct inode *inode, > + struct vm_area_struct *vma, pgoff_t index, > + bool global_huge) > +{ > + return 0; > +} > + > #define transparent_hugepage_flags 0UL > > #define thp_get_unmapped_area NULL > diff --git a/mm/shmem.c b/mm/shmem.c > index d495c0701a83..aa85df9c662a 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1622,7 +1622,7 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t limit_gfp) > } > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > -static unsigned long shmem_allowable_huge_orders(struct inode *inode, > +unsigned long shmem_allowable_huge_orders(struct inode *inode, > struct vm_area_struct *vma, pgoff_t index, > bool global_huge) > { > @@ -1707,13 +1707,6 @@ static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault > return orders; > } > #else > -static unsigned long shmem_allowable_huge_orders(struct inode *inode, > - struct vm_area_struct *vma, pgoff_t index, > - bool global_huge) > -{ > - return 0; > -} > - > static unsigned long shmem_suitable_orders(struct inode *inode, struct vm_fault *vmf, > struct address_space *mapping, pgoff_t index, > unsigned long orders)