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Wed, 11 Feb 2026 21:19:23 -0500 X-MC-Unique: cOnx6XVFNbyLbnIWZHOlBQ-1 X-Mimecast-MFC-AGG-ID: cOnx6XVFNbyLbnIWZHOlBQ_1770862762 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9D9EF1800367; Thu, 12 Feb 2026 02:19:22 +0000 (UTC) Received: from h1.redhat.com (unknown [10.22.80.91]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0EDA01956056; Thu, 12 Feb 2026 02:19:12 +0000 (UTC) From: Nico Pache To: linux-kernel@vger.kernel.org, linux-mm@kvack.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, jackmanb@google.com, jack@suse.cz, 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 v1 3/5] mm/khugepaged: define COLLAPSE_MAX_PTES_LIMIT as HPAGE_PMD_NR - 1 Date: Wed, 11 Feb 2026 19:18:33 -0700 Message-ID: <20260212021835.17755-4-npache@redhat.com> In-Reply-To: <20260212021835.17755-1-npache@redhat.com> References: <20260212021835.17755-1-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 3.0 on 10.30.177.17 Content-Type: text/plain; charset="utf-8" The value (HPAGE_PMD_NR - 1) is used often in the khugepaged code to signify the limit of the max_ptes_* values. Add a define for this to increase code readability and reuse. Signed-off-by: Nico Pache Acked-by: Pedro Falcato Reviewed-by: Zi Yan --- mm/khugepaged.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index c362b3b2e08a..3dcce6018f20 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -85,6 +85,7 @@ static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait); * * Note that these are only respected if collapse was initiated by khugepa= ged. */ +#define COLLAPSE_MAX_PTES_LIMIT (HPAGE_PMD_NR - 1) unsigned int khugepaged_max_ptes_none __read_mostly; static unsigned int khugepaged_max_ptes_swap __read_mostly; static unsigned int khugepaged_max_ptes_shared __read_mostly; @@ -252,7 +253,7 @@ static ssize_t max_ptes_none_store(struct kobject *kobj, unsigned long max_ptes_none; =20 err =3D kstrtoul(buf, 10, &max_ptes_none); - if (err || max_ptes_none > HPAGE_PMD_NR - 1) + if (err || max_ptes_none > COLLAPSE_MAX_PTES_LIMIT) return -EINVAL; =20 khugepaged_max_ptes_none =3D max_ptes_none; @@ -277,7 +278,7 @@ static ssize_t max_ptes_swap_store(struct kobject *kobj, unsigned long max_ptes_swap; =20 err =3D kstrtoul(buf, 10, &max_ptes_swap); - if (err || max_ptes_swap > HPAGE_PMD_NR - 1) + if (err || max_ptes_swap > COLLAPSE_MAX_PTES_LIMIT) return -EINVAL; =20 khugepaged_max_ptes_swap =3D max_ptes_swap; @@ -303,7 +304,7 @@ static ssize_t max_ptes_shared_store(struct kobject *ko= bj, unsigned long max_ptes_shared; =20 err =3D kstrtoul(buf, 10, &max_ptes_shared); - if (err || max_ptes_shared > HPAGE_PMD_NR - 1) + if (err || max_ptes_shared > COLLAPSE_MAX_PTES_LIMIT) return -EINVAL; =20 khugepaged_max_ptes_shared =3D max_ptes_shared; @@ -384,7 +385,7 @@ int __init khugepaged_init(void) return -ENOMEM; =20 khugepaged_pages_to_scan =3D HPAGE_PMD_NR * 8; - khugepaged_max_ptes_none =3D HPAGE_PMD_NR - 1; + khugepaged_max_ptes_none =3D COLLAPSE_MAX_PTES_LIMIT; khugepaged_max_ptes_swap =3D HPAGE_PMD_NR / 8; khugepaged_max_ptes_shared =3D HPAGE_PMD_NR / 2; =20 @@ -1869,7 +1870,7 @@ static enum scan_result collapse_file(struct mm_struc= t *mm, unsigned long addr, bool is_shmem =3D shmem_file(file); =20 VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); - VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); + VM_BUG_ON(start & (COLLAPSE_MAX_PTES_LIMIT)); =20 result =3D alloc_charge_folio(&new_folio, mm, cc); if (result !=3D SCAN_SUCCEED) @@ -2209,7 +2210,7 @@ static enum scan_result collapse_file(struct mm_struc= t *mm, unsigned long addr, * unwritten page. */ folio_mark_uptodate(new_folio); - folio_ref_add(new_folio, HPAGE_PMD_NR - 1); + folio_ref_add(new_folio, COLLAPSE_MAX_PTES_LIMIT); =20 if (is_shmem) folio_mark_dirty(new_folio); @@ -2303,7 +2304,7 @@ static enum scan_result hpage_collapse_scan_file(stru= ct mm_struct *mm, unsigned memset(cc->node_load, 0, sizeof(cc->node_load)); nodes_clear(cc->alloc_nmask); rcu_read_lock(); - xas_for_each(&xas, folio, start + HPAGE_PMD_NR - 1) { + xas_for_each(&xas, folio, start + COLLAPSE_MAX_PTES_LIMIT) { if (xas_retry(&xas, folio)) continue; =20 --=20 2.53.0