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 C58FBF9E6 for ; Mon, 1 Jul 2024 08:18:14 +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=1719821896; cv=none; b=nvgSpoHNcvZvQxpY/ex/4YA3wJuCJheOGCJ0UBf5UkUD0Iw6jaib08f9wx+nd3fUK+X4MTBLhFdjzXS2Y+LkrgeEVGS8xe8SwZFpKi4u6maqCVhVyN2RDyaeIWa4A3fdeTfjc61z3QXjwvPQZnthZS9YPf72H3GNk9tiH2hdr6k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719821896; c=relaxed/simple; bh=b3UDwcDEu2LvlS8QtfJ25eHsFFyZTqOr+BJXZTmzyDM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=VWJsO8poGuAh7poDmEpLW+Sv2ftgSYWvJgVMFrcV7FJpaMJ57Oamy4SAKPwur7vpiJAa/IdPNjqyEvcGlx0q2mpvDVJqhb8hE2wsjZkKHXeJIVXjDXTxK2roprEVifvkpHz+DCd6bjdOfik9jTdc5O1F426OKqcEHAopPcN5Ixc= 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 D1A6A339; Mon, 1 Jul 2024 01:18:38 -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 F2F703F766; Mon, 1 Jul 2024 01:18:11 -0700 (PDT) Message-ID: <4516ebbe-5d88-423a-bc45-dfb1eb6adc2d@arm.com> Date: Mon, 1 Jul 2024 09:18:10 +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 v2 1/2] mm: add per-order mTHP split counters Content-Language: en-GB To: Lance Yang , akpm@linux-foundation.org Cc: dj456119@gmail.com, 21cnbao@gmail.com, david@redhat.com, shy828301@gmail.com, ziy@nvidia.com, libang.li@antgroup.com, baolin.wang@linux.alibaba.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mingzhe Yang References: <20240628130750.73097-1-ioworker0@gmail.com> <20240628130750.73097-2-ioworker0@gmail.com> From: Ryan Roberts In-Reply-To: <20240628130750.73097-2-ioworker0@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 28/06/2024 14:07, Lance Yang wrote: > Currently, the split counters in THP statistics no longer include > PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split > counters to monitor the frequency of mTHP splits. This will help developers > better analyze and optimize system performance. > > /sys/kernel/mm/transparent_hugepage/hugepages-/stats > split > split_failed > split_deferred > > Signed-off-by: Mingzhe Yang > Signed-off-by: Lance Yang LGTM! Reviewed-by: Ryan Roberts > --- > include/linux/huge_mm.h | 3 +++ > mm/huge_memory.c | 19 ++++++++++++++----- > 2 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 212cca384d7e..cee3c5da8f0e 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -284,6 +284,9 @@ enum mthp_stat_item { > MTHP_STAT_FILE_ALLOC, > MTHP_STAT_FILE_FALLBACK, > MTHP_STAT_FILE_FALLBACK_CHARGE, > + MTHP_STAT_SPLIT, > + MTHP_STAT_SPLIT_FAILED, > + MTHP_STAT_SPLIT_DEFERRED, > __MTHP_STAT_COUNT > }; > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index c7ce28f6b7f3..a633206375af 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -559,6 +559,9 @@ DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK); > DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC); > DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK); > DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_FALLBACK_CHARGE); > +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT); > +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED); > +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED); > > static struct attribute *stats_attrs[] = { > &anon_fault_alloc_attr.attr, > @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = { > &file_alloc_attr.attr, > &file_fallback_attr.attr, > &file_fallback_charge_attr.attr, > + &split_attr.attr, > + &split_failed_attr.attr, > + &split_deferred_attr.attr, > NULL, > }; > > @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order); > struct anon_vma *anon_vma = NULL; > struct address_space *mapping = NULL; > - bool is_thp = folio_test_pmd_mappable(folio); > + int order = folio_order(folio); > int extra_pins, ret; > pgoff_t end; > bool is_hzp; > @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); > > - if (new_order >= folio_order(folio)) > + if (new_order >= order) > return -EINVAL; > > if (folio_test_anon(folio)) { > @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, > i_mmap_unlock_read(mapping); > out: > xas_destroy(&xas); > - if (is_thp) > + if (order >= HPAGE_PMD_ORDER) > count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); > + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED); > return ret; > } > > @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio) > #ifdef CONFIG_MEMCG > struct mem_cgroup *memcg = folio_memcg(folio); > #endif > + int order = folio_order(folio); > unsigned long flags; > > /* > * Order 1 folios have no space for a deferred list, but we also > * won't waste much memory by not adding them to the deferred list. > */ > - if (folio_order(folio) <= 1) > + if (order <= 1) > return; > > /* > @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio) > > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > if (list_empty(&folio->_deferred_list)) { > - if (folio_test_pmd_mappable(folio)) > + if (order >= HPAGE_PMD_ORDER) > count_vm_event(THP_DEFERRED_SPLIT_PAGE); > + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED); > list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); > ds_queue->split_queue_len++; > #ifdef CONFIG_MEMCG