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 7DC2E1DE3DE for ; Tue, 17 Dec 2024 06:53:30 +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=1734418412; cv=none; b=Jlmk3kXQ2T+BvyUfHxgv7IS8HuJ9+zWts3U3KrKv9VFcRtTcsU1C+F1ooX0ou5ywmJmURliUy86aQCjxS5iLNUngiJOC/PgG6mw33mRmQ/EViaMV3UPf50aSwRY5x32+O40tC2LZVLewKIYeUyro48P7C1YzPXYtJJEcp53005U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734418412; c=relaxed/simple; bh=1v1fPD9iQX9kwhZSBJkQEwh/QHpcMY2sWw4DI5eCol4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=azle1btHhUkFwG2vnlbaObn55Jkp0AdDiWOrgA5f+penfRirCliTlEWLQ1zSfaRITc8fne4DF2CJ8/ov/QFGyyJ2jaVCGf5neCH8Im7baGWh063R4YE1tPIygSWf8Wn83Wb8EPK69PxOWG8oHnoK3aQu8TBEgRLm1MlSeEpbWUg= 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 A19701007; Mon, 16 Dec 2024 22:53:57 -0800 (PST) Received: from [10.57.91.184] (unknown [10.57.91.184]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8D7B03F528; Mon, 16 Dec 2024 22:53:24 -0800 (PST) Message-ID: <46939efe-cf79-4dcd-9e47-9340956feb03@arm.com> Date: Tue, 17 Dec 2024 06:53:22 +0000 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: [RFC PATCH 02/12] khugepaged: Generalize alloc_charge_folio() Content-Language: en-GB To: Dev Jain , akpm@linux-foundation.org, david@redhat.com, willy@infradead.org, kirill.shutemov@linux.intel.com Cc: anshuman.khandual@arm.com, catalin.marinas@arm.com, cl@gentwo.org, vbabka@suse.cz, mhocko@suse.com, apopple@nvidia.com, dave.hansen@linux.intel.com, will@kernel.org, baohua@kernel.org, jack@suse.cz, srivatsa@csail.mit.edu, haowenchao22@gmail.com, hughd@google.com, aneesh.kumar@kernel.org, yang@os.amperecomputing.com, peterx@redhat.com, ioworker0@gmail.com, wangkefeng.wang@huawei.com, ziy@nvidia.com, jglisse@google.com, surenb@google.com, vishal.moola@gmail.com, zokeefe@google.com, zhengqi.arch@bytedance.com, jhubbard@nvidia.com, 21cnbao@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20241216165105.56185-1-dev.jain@arm.com> <20241216165105.56185-3-dev.jain@arm.com> From: Ryan Roberts In-Reply-To: <20241216165105.56185-3-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 16/12/2024 16:50, Dev Jain wrote: > Pass order to alloc_charge_folio() and update mTHP statistics. > > Signed-off-by: Dev Jain > --- > include/linux/huge_mm.h | 2 ++ > mm/huge_memory.c | 4 ++++ > mm/khugepaged.c | 13 +++++++++---- > 3 files changed, 15 insertions(+), 4 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 93e509b6c00e..8b6d0fed99b3 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -119,6 +119,8 @@ enum mthp_stat_item { > MTHP_STAT_ANON_FAULT_ALLOC, > MTHP_STAT_ANON_FAULT_FALLBACK, > MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE, > + MTHP_STAT_ANON_COLLAPSE_ALLOC, > + MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED, > MTHP_STAT_ZSWPOUT, > MTHP_STAT_SWPIN, > MTHP_STAT_SWPIN_FALLBACK, > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 2da5520bfe24..2e582fad4c77 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -615,6 +615,8 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name) > DEFINE_MTHP_STAT_ATTR(anon_fault_alloc, MTHP_STAT_ANON_FAULT_ALLOC); > DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK); > DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); > +DEFINE_MTHP_STAT_ATTR(anon_collapse_alloc, MTHP_STAT_ANON_COLLAPSE_ALLOC); > +DEFINE_MTHP_STAT_ATTR(anon_collapse_alloc_failed, MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED); > DEFINE_MTHP_STAT_ATTR(zswpout, MTHP_STAT_ZSWPOUT); > DEFINE_MTHP_STAT_ATTR(swpin, MTHP_STAT_SWPIN); > DEFINE_MTHP_STAT_ATTR(swpin_fallback, MTHP_STAT_SWPIN_FALLBACK); > @@ -636,6 +638,8 @@ static struct attribute *anon_stats_attrs[] = { > &anon_fault_alloc_attr.attr, > &anon_fault_fallback_attr.attr, > &anon_fault_fallback_charge_attr.attr, > + &anon_collapse_alloc_attr.attr, > + &anon_collapse_alloc_failed_attr.attr, > #ifndef CONFIG_SHMEM > &zswpout_attr.attr, > &swpin_attr.attr, > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 95643e6e5f31..02cd424b8e48 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1073,21 +1073,26 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm, > } > > static int alloc_charge_folio(struct folio **foliop, struct mm_struct *mm, > - struct collapse_control *cc) > + int order, struct collapse_control *cc) > { > gfp_t gfp = (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() : > GFP_TRANSHUGE); > int node = hpage_collapse_find_target_node(cc); > struct folio *folio; > > - folio = __folio_alloc(gfp, HPAGE_PMD_ORDER, node, &cc->alloc_nmask); > + folio = __folio_alloc(gfp, order, node, &cc->alloc_nmask); > if (!folio) { > *foliop = NULL; > count_vm_event(THP_COLLAPSE_ALLOC_FAILED); > + if (order != HPAGE_PMD_ORDER) > + count_mthp_stat(order, MTHP_STAT_ANON_COLLAPSE_ALLOC_FAILED); Bug? We should be calling count_mthp_stat() for all orders, but only calling count_vm_event(THP_*) for PMD_ORDER, as per pattern laid out by other mTHP stats. The aim is for existing THP stats (which are implicitly only counting PMD-sized THP) to continue only to count PMD-sized THP. It's a userspace ABI and we were scared of the potential to break things if we changed the existing counters' semantics. > return SCAN_ALLOC_HUGE_PAGE_FAIL; > } > > count_vm_event(THP_COLLAPSE_ALLOC); > + if (order != HPAGE_PMD_ORDER) > + count_mthp_stat(order, MTHP_STAT_ANON_COLLAPSE_ALLOC); Same problem. Also, I agree with Baolin that we don't want "anon" in the title. This is a generic path used for file-backed memory. So once you fix the bug, the new stats will also be counting the file-backed memory too (although for now, only for PMD_ORDER). > + > if (unlikely(mem_cgroup_charge(folio, mm, gfp))) { > folio_put(folio); > *foliop = NULL; > @@ -1124,7 +1129,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, > */ > mmap_read_unlock(mm); > > - result = alloc_charge_folio(&folio, mm, cc); > + result = alloc_charge_folio(&folio, mm, order, cc); Where is order coming from? I'm guessing that's added later, so this patch won't compile on it's own? Perhaps HPAGE_PMD_ORDER for now? > if (result != SCAN_SUCCEED) > goto out_nolock; > > @@ -1850,7 +1855,7 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr, > VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); > VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); > > - result = alloc_charge_folio(&new_folio, mm, cc); > + result = alloc_charge_folio(&new_folio, mm, HPAGE_PMD_ORDER, cc); > if (result != SCAN_SUCCEED) > goto out; >