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Wed, 25 Feb 2026 22:23:40 -0500 X-MC-Unique: R0vaQ4QvOYyxoI4YeILgQw-1 X-Mimecast-MFC-AGG-ID: R0vaQ4QvOYyxoI4YeILgQw_1772076219 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BCB3D1956096; Thu, 26 Feb 2026 03:23:39 +0000 (UTC) Received: from h1.redhat.com (unknown [10.22.64.173]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2F5163003D88; Thu, 26 Feb 2026 03:23:29 +0000 (UTC) From: Nico Pache To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Cc: aarcange@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, catalin.marinas@arm.com, cl@gentwo.org, corbet@lwn.net, dave.hansen@linux.intel.com, david@kernel.org, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, jackmanb@google.com, jannh@google.com, jglisse@google.com, joshua.hahnjy@gmail.com, kas@kernel.org, lance.yang@linux.dev, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, mathieu.desnoyers@efficios.com, matthew.brost@intel.com, mhiramat@kernel.org, mhocko@suse.com, npache@redhat.com, peterx@redhat.com, pfalcato@suse.de, rakie.kim@sk.com, raquini@redhat.com, rdunlap@infradead.org, richard.weiyang@gmail.com, rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org, ryan.roberts@arm.com, shivankg@amd.com, sunnanyong@huawei.com, surenb@google.com, thomas.hellstrom@linux.intel.com, tiwai@suse.de, usamaarif642@gmail.com, vbabka@suse.cz, vishal.moola@gmail.com, wangkefeng.wang@huawei.com, will@kernel.org, willy@infradead.org, yang@os.amperecomputing.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, zokeefe@google.com Subject: [PATCH mm-unstable v15 02/13] mm/khugepaged: generalize alloc_charge_folio() Date: Wed, 25 Feb 2026 20:23:26 -0700 Message-ID: <20260226032326.232770-1-npache@redhat.com> In-Reply-To: <20260226031741.230674-1-npache@redhat.com> References: <20260226031741.230674-1-npache@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Content-Type: text/plain; charset="utf-8" From: Dev Jain Pass order to alloc_charge_folio() and update mTHP statistics. Reviewed-by: Wei Yang Reviewed-by: Lance Yang Reviewed-by: Baolin Wang Reviewed-by: Lorenzo Stoakes Reviewed-by: Zi Yan Co-developed-by: Nico Pache Signed-off-by: Nico Pache Signed-off-by: Dev Jain Acked-by: David Hildenbrand (Arm) --- Documentation/admin-guide/mm/transhuge.rst | 8 ++++++++ include/linux/huge_mm.h | 2 ++ mm/huge_memory.c | 4 ++++ mm/khugepaged.c | 17 +++++++++++------ 4 files changed, 25 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/adm= in-guide/mm/transhuge.rst index 5fbc3d89bb07..c51932e6275d 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -639,6 +639,14 @@ anon_fault_fallback_charge instead falls back to using huge pages with lower orders or small pages even though the allocation was successful. =20 +collapse_alloc + is incremented every time a huge page is successfully allocated for a + khugepaged collapse. + +collapse_alloc_failed + is incremented every time a huge page allocation fails during a + khugepaged collapse. + zswpout is incremented every time a huge page is swapped out to zswap in one piece without splitting. diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index bd7f0e1d8094..9941fc6d7bd8 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -128,6 +128,8 @@ enum mthp_stat_item { MTHP_STAT_ANON_FAULT_ALLOC, MTHP_STAT_ANON_FAULT_FALLBACK, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE, + MTHP_STAT_COLLAPSE_ALLOC, + MTHP_STAT_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 a688d5ff806e..228f35e962b9 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -624,6 +624,8 @@ static struct kobj_attribute _name##_attr =3D __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_FAL= LBACK_CHARGE); +DEFINE_MTHP_STAT_ATTR(collapse_alloc, MTHP_STAT_COLLAPSE_ALLOC); +DEFINE_MTHP_STAT_ATTR(collapse_alloc_failed, MTHP_STAT_COLLAPSE_ALLOC_FAIL= ED); 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); @@ -689,6 +691,8 @@ static struct attribute *any_stats_attrs[] =3D { #endif &split_attr.attr, &split_failed_attr.attr, + &collapse_alloc_attr.attr, + &collapse_alloc_failed_attr.attr, NULL, }; =20 diff --git a/mm/khugepaged.c b/mm/khugepaged.c index c7f2c4a90910..a9b645402b7f 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1061,21 +1061,26 @@ static enum scan_result __collapse_huge_page_swapin= (struct mm_struct *mm, } =20 static enum scan_result alloc_charge_folio(struct folio **foliop, struct m= m_struct *mm, - struct collapse_control *cc) + struct collapse_control *cc, unsigned int order) { gfp_t gfp =3D (cc->is_khugepaged ? alloc_hugepage_khugepaged_gfpmask() : GFP_TRANSHUGE); int node =3D collapse_find_target_node(cc); struct folio *folio; =20 - folio =3D __folio_alloc(gfp, HPAGE_PMD_ORDER, node, &cc->alloc_nmask); + folio =3D __folio_alloc(gfp, order, node, &cc->alloc_nmask); if (!folio) { *foliop =3D NULL; - count_vm_event(THP_COLLAPSE_ALLOC_FAILED); + if (is_pmd_order(order)) + count_vm_event(THP_COLLAPSE_ALLOC_FAILED); + count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC_FAILED); return SCAN_ALLOC_HUGE_PAGE_FAIL; } =20 - count_vm_event(THP_COLLAPSE_ALLOC); + if (is_pmd_order(order)) + count_vm_event(THP_COLLAPSE_ALLOC); + count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC); + if (unlikely(mem_cgroup_charge(folio, mm, gfp))) { folio_put(folio); *foliop =3D NULL; @@ -1111,7 +1116,7 @@ static enum scan_result collapse_huge_page(struct mm_= struct *mm, unsigned long a */ mmap_read_unlock(mm); =20 - result =3D alloc_charge_folio(&folio, mm, cc); + result =3D alloc_charge_folio(&folio, mm, cc, HPAGE_PMD_ORDER); if (result !=3D SCAN_SUCCEED) goto out_nolock; =20 @@ -1891,7 +1896,7 @@ static enum scan_result collapse_file(struct mm_struc= t *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)); =20 - result =3D alloc_charge_folio(&new_folio, mm, cc); + result =3D alloc_charge_folio(&new_folio, mm, cc, HPAGE_PMD_ORDER); if (result !=3D SCAN_SUCCEED) goto out; =20 --=20 2.53.0