From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-80.mta1.migadu.com [95.215.58.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1DA43B101C for ; Fri, 2 Oct 2026 09:57:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790935022; cv=none; b=AoNYJ3on6sFRZgC6ewXmN5YTZa1nowWpItJPu24NYSyrj4kliHI5q+PufZ/aCFobnaq2hcwIFnGaI7SKTWlYRaTOhUX17LNYnI2UYzNvwB4OtUFuHtHZTL7VEQPEA1ogxncZjhmlCpCMX7VCHelvAmVx/VTfeNoAYTtfQ9Ok1qI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790935022; c=relaxed/simple; bh=U7fl/g2rQtBLEOOrRTOeLDCwF2LzhxQL9fohkaqezco=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KlTXjlHbc0evOnygdGhZ4L/0+JWjA0mFckzRJFgi56S3Gl2f29KUf8P1HoReeJoDUCQb+JxOgL9NabaX2aoJjaxDKQzRqlm3MWmi/tEhVa2DASd6aVC4WXv7MHTWJ3DCoZIPc49749ZyFKDgOb8wnlWn8Ei7W/Um7hiVVmNPwU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=V+HGp6iu; arc=none smtp.client-ip=95.215.58.80 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="V+HGp6iu" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=U7fl/g2rQtBLEOOrRTOeLDCwF2LzhxQL9fohkaqezco=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790935018; v=1; x=1791539818; b=V+HGp6iuRhxNJlToyyu4Db5rTKQ0jAz7Rn/JbvJ5z05atfpJfZbnbUv/vTkap/DEdJbvXJMi 2m1c2ACvb3JW3sh3jhhVcxiczSrkIdiSP8VUy2B1gSI5dFBt54WgUhu2OT7RHP9BryHN0/taxCz Q84662Jr5/kV7aIUeGEVhtR0= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 780e5e8d7edcc9b9; Fri, 02 Oct 2026 09:56:57 +0000 X-Mizu-Trace-ID: 780e5e8d7edcc9b9 X-Migadu-Flow: FLOW_OUT From: Usama Arif To: Andrew Morton , david@kernel.org, chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com, linux-mm@kvack.org Cc: ying.huang@linux.alibaba.com, Baoquan He , willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, Nico Pache , Liam R. Howlett , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, yosry@kernel.org, qi.zheng@linux.dev, luizcap@redhat.com, kernel-team@meta.com, Usama Arif Subject: [PATCH v8 16/30] fs/proc: account PMD swap entries in smaps Date: Fri, 2 Oct 2026 02:52:30 -0700 Message-ID: <20261002095503.3585565-17-usama.arif@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261002095503.3585565-1-usama.arif@linux.dev> References: <20261002095503.3585565-1-usama.arif@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit smaps_pmd_entry() derives a page from a non-present PMD and gives up if it cannot. A PMD swap entry carries no PFN, so a swapped-out THP is missing from both Swap and SwapPss. The slots of a PMD swap entry can have different swap reference counts, so SwapPss has to be computed one slot at a time rather than divided once. Factor that loop out of smaps_pte_entry() and call it from both levels, then return early: a swapped-out THP is not resident and must not be added to AnonHugePages or Rss. While touching PMD softleaf accounting, match the PTE path and treat device-private PMD entries as fake-present. This lets smaps use mapcount-based PSS and private/shared accounting instead of treating them like migration entries. Signed-off-by: Usama Arif --- fs/proc/task_mmu.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 24425e2308951..97c3fd7acf15d 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -957,6 +957,25 @@ static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk) #endif } +static void smaps_account_swap(struct mem_size_stats *mss, + softleaf_t entry, unsigned long nr_pages) +{ + mss->swap += nr_pages << PAGE_SHIFT; + do { + int swapcount = swp_swapcount(entry); + + if (swapcount >= 2) { + u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; + + do_div(pss_delta, swapcount); + mss->swap_pss += pss_delta; + } else { + mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; + } + entry.val++; + } while (--nr_pages); +} + static void smaps_pte_entry(pte_t *pte, unsigned long addr, struct mm_walk *walk) { @@ -978,18 +997,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr, const softleaf_t entry = softleaf_from_pte(ptent); if (softleaf_is_swap(entry)) { - int mapcount; - - mss->swap += PAGE_SIZE; - mapcount = swp_swapcount(entry); - if (mapcount >= 2) { - u64 pss_delta = (u64)PAGE_SIZE << PSS_SHIFT; - - do_div(pss_delta, mapcount); - mss->swap_pss += pss_delta; - } else { - mss->swap_pss += (u64)PAGE_SIZE << PSS_SHIFT; - } + smaps_account_swap(mss, entry, 1); } else if (softleaf_has_pfn(entry)) { if (softleaf_is_device_private(entry)) present = true; @@ -1022,8 +1030,15 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, } else if (unlikely(thp_migration_supported())) { const softleaf_t entry = softleaf_from_pmd(*pmd); - if (softleaf_has_pfn(entry)) + if (softleaf_is_swap(entry)) { + smaps_account_swap(mss, entry, HPAGE_PMD_NR); + return; + } + if (softleaf_has_pfn(entry)) { + if (softleaf_is_device_private(entry)) + present = true; page = softleaf_to_page(entry); + } } if (IS_ERR_OR_NULL(page)) return; -- 2.53.0-Meta