From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 C664917C7C4 for ; Wed, 11 Sep 2024 10:52:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726051971; cv=none; b=liMHKkcx1RGeVM9SP9jofEbDcNtlv1K+W8FkTUmBfCgE3O2C+1p1PEOyolRXY5Ezr4IzYIA1HuLs3NbAiFyysMC0Ur6+4WplBgDAn2qQvIaJ88plnGUG1DBeIPXwDZwT1QIb4MpdfCMxcqkYBWV2CTXnrE6JPRfXcOubvjD8hsU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726051971; c=relaxed/simple; bh=t+oWOl4YBiTCEHWcFOwzcj7P1DA7i/iyrk8eb2HIakA=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=J+kllXxKdRm6LH/34JI8kyEhAUPMdXARQih0BdrK7NHrxr0l6wAMYE3kEukvqSebpuoyM2YCvzaOioknkaB+V8nIWqMguWDO0WfQGbYix1ZzVnnffyynLyIE3znawPAeOPtR9Y5ASMi6Lwf/ig21Q33nEa7mdUgOmGKT10QbmyY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.194]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4X3cnk1rXkzyRLW; Wed, 11 Sep 2024 18:51:38 +0800 (CST) Received: from dggpemf100008.china.huawei.com (unknown [7.185.36.138]) by mail.maildlp.com (Postfix) with ESMTPS id 26086140156; Wed, 11 Sep 2024 18:52:45 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemf100008.china.huawei.com (7.185.36.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 11 Sep 2024 18:52:44 +0800 Message-ID: <170988b0-db8a-4612-a70c-b20ea2d4c020@huawei.com> Date: Wed, 11 Sep 2024 18:52:43 +0800 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 v3 1/2] mm: Abstract THP allocation Content-Language: en-US To: Dev Jain , , , , CC: , , , , , , , , , , , , , , , , , , , , , References: <20240911065600.1002644-1-dev.jain@arm.com> <20240911065600.1002644-2-dev.jain@arm.com> From: Kefeng Wang In-Reply-To: <20240911065600.1002644-2-dev.jain@arm.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemf100008.china.huawei.com (7.185.36.138) On 2024/9/11 14:55, Dev Jain wrote: > In preparation for the second patch, abstract away the THP allocation > logic present in the create_huge_pmd() path, which corresponds to the > faulting case when no page is present. > > There should be no functional change as a result of applying > this patch. > > Signed-off-by: Dev Jain > --- > mm/huge_memory.c | 110 +++++++++++++++++++++++++++++------------------ > 1 file changed, 67 insertions(+), 43 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 67c86a5d64a6..b96a1ff2bf40 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -943,47 +943,88 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, > } > EXPORT_SYMBOL_GPL(thp_get_unmapped_area); > > -static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, > - struct page *page, gfp_t gfp) > +static struct folio *pmd_thp_fault_alloc(gfp_t gfp, struct vm_area_struct *vma, > + unsigned long haddr, unsigned long addr) > { > - struct vm_area_struct *vma = vmf->vma; > - struct folio *folio = page_folio(page); > - pgtable_t pgtable; > - unsigned long haddr = vmf->address & HPAGE_PMD_MASK; > - vm_fault_t ret = 0; > + const int order = HPAGE_PMD_ORDER; Maybe move vma_thp_gfp_mask() into this function too. > + struct folio *folio = vma_alloc_folio(gfp, order, vma, haddr, true); > > - VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); > + if (unlikely(!folio)) { > + count_vm_event(THP_FAULT_FALLBACK); > + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK); > + goto out; > + } > > + VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); > if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { > folio_put(folio); > count_vm_event(THP_FAULT_FALLBACK); > count_vm_event(THP_FAULT_FALLBACK_CHARGE); > - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK); > - count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); > - return VM_FAULT_FALLBACK; > + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK); > + count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); > + goto out; We need to return NULL here as folio not set to null, > } > folio_throttle_swaprate(folio, gfp); > > - pgtable = pte_alloc_one(vma->vm_mm); > - if (unlikely(!pgtable)) { > - ret = VM_FAULT_OOM; > - goto release; > - } > - > - folio_zero_user(folio, vmf->address); > + folio_zero_user(folio, addr); > /* > * The memory barrier inside __folio_mark_uptodate makes sure that > * folio_zero_user writes become visible before the set_pmd_at() > * write. > */ > __folio_mark_uptodate(folio); > +out: > + return folio; > +} > +