From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f50.google.com (mail-qv1-f50.google.com [209.85.219.50]) (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 73CED19AD5C; Tue, 13 Aug 2024 12:03:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723550633; cv=none; b=B9LuEFYe00YARzU8YdS3QlwN4S3k6EBF5IWTPU1aKvMpxetrLx/dPI9cdTn3qzS9UbNym7qqfVyNotgh8tGAWIeXqymJmATOi7qXnyxFRzEa7zYpR1+Fll62IyF6LahoD05EpMWj5qy/I1ZBnlaFFG3SNJW4CDoS0kjBSZ04iK8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723550633; c=relaxed/simple; bh=J8iCl8NFugwQEvqBetgBik9A5B1qMEYPkoEZhRroEr0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X9Bpj0gzvPUlTvi7E/m7Eq/D/MZWfqbvV3B6apkRJbJEvJpsQT37gBvXeYrYGvPraltCNxrUlSCWh3gOP5zEbXCF47vmRETvZrETFLsm2uyMtElTDMqRmbePBC3TQp4+f9NDuY1FiPFjLR7hcODAT+4yHLIQ1Rpp3GsFH4+Ep+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Eh526LHw; arc=none smtp.client-ip=209.85.219.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Eh526LHw" Received: by mail-qv1-f50.google.com with SMTP id 6a1803df08f44-6b79fc76d03so30950326d6.1; Tue, 13 Aug 2024 05:03:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1723550630; x=1724155430; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=fpDDmqOnJijcRyZ/zRVr0dfh/EUV8mM0nwD7hiV/Er4=; b=Eh526LHwFRietxpi0Yr2Qp+4lWG2PCwUeOb3l5q8sAcOy/AIgIyXLRAyqONFd9/eir CLa2NoqdvA6LFcjJ9Qwlj2apGGAbzbGxuCFBuf8uZgrdbgf5Io6xUDoh1PWXIobwY9Tx 7tJYrKqBdYvrmqwmyIXqfpvCy2mljWdMZPBv01yAm8jE8U21RknRKhipjM2SadF6o3kn Nkn0ARK8Sz3k7nYDf+C3V3CGT8VTl+IF3XBtiohKEA/ub+nFujpvmdie4KipHWJ0aZOn JkZi48aN5+um0QRGtaWeEKahRMgRCoX7Vaz+lMQCS5Vf42D6dKhcANz9XVNZPIumeitc uQWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723550630; x=1724155430; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=fpDDmqOnJijcRyZ/zRVr0dfh/EUV8mM0nwD7hiV/Er4=; b=Hi0wWKoYUwLkL1vy21DaZ5nGFbhKVS7wNPhg/U+nLI5rRYPjja2QTklI/Uq02J5F38 u3SIfKSb1YlqvFktyhONifMDgzmzC9DDXAE5NUlGQRItsyOTJg0jXIhhR+G2B1K8FxW7 Wsw+rUlo0bGoCo6Qmbk0ZWMl9b50fpUWHX0i2UFk0DRoXRUMzKlmWa41aTcmNWpt/1+u 2Azt7NCcJ/q+T9y5jH1EEhJfEYXWt3WoDDhjYe33fZJjQbP9x93E2BWImOHBWPC7Mmjz vpz/SfhNHbGRJon4bEv0El41BeSS4kRsl5HY2lxnnsBidAIDW11Kqt6cvB5aGkP8GPbm Qh9Q== X-Forwarded-Encrypted: i=1; AJvYcCUOwEiNhwxFk6X9MkWJ4dAKGTLw/i92dKVga3nPmQnK0nK2A8/xukAwEuD781531/6mJtfF8WzfFwAF2moMWLyEtCteM85CG5tSP3s9iHu0DBp6AK4fhlwkOh3TOjYRZ3esjqsIqXum X-Gm-Message-State: AOJu0YyevFJofaxCJ1m8xnRfGBBML2LeW8bmGuU/CzGyhUncbsHjSCCi 6/lZZ709T9mSWmop/OKKi1NrUQ7sLH1HQvTqENKLb5vyaM76F39o X-Google-Smtp-Source: AGHT+IG/p4KHdjtbRHl8jrRDtZpiTzA00oY1agex2KO6TAfMpoEbk5fNk2V++Y8FeIZ5s4O/KzF07g== X-Received: by 2002:a05:6214:5f0b:b0:6b7:980b:e0ac with SMTP id 6a1803df08f44-6bf4f7e2315mr29329476d6.32.1723550630417; Tue, 13 Aug 2024 05:03:50 -0700 (PDT) Received: from localhost (fwdproxy-ash-011.fbsv.net. [2a03:2880:20ff:b::face:b00c]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6bd82c81cd0sm33464656d6.53.2024.08.13.05.03.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Aug 2024 05:03:50 -0700 (PDT) From: Usama Arif To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, roman.gushchin@linux.dev, yuzhao@google.com, david@redhat.com, baohua@kernel.org, ryan.roberts@arm.com, rppt@kernel.org, willy@infradead.org, cerasuolodomenico@gmail.com, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@meta.com, Usama Arif Subject: [PATCH v3 6/6] mm: add sysfs entry to disable splitting underutilized THPs Date: Tue, 13 Aug 2024 13:02:49 +0100 Message-ID: <20240813120328.1275952-7-usamaarif642@gmail.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20240813120328.1275952-1-usamaarif642@gmail.com> References: <20240813120328.1275952-1-usamaarif642@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If disabled, THPs faulted in or collapsed will not be added to _deferred_list, and therefore won't be considered for splitting under memory pressure if underutilized. Signed-off-by: Usama Arif --- mm/huge_memory.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6b32b2d4ab1e..b4d72479330d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -74,6 +74,7 @@ static unsigned long deferred_split_count(struct shrinker *shrink, struct shrink_control *sc); static unsigned long deferred_split_scan(struct shrinker *shrink, struct shrink_control *sc); +static bool split_underutilized_thp = true; static atomic_t huge_zero_refcount; struct folio *huge_zero_folio __read_mostly; @@ -439,6 +440,27 @@ static ssize_t hpage_pmd_size_show(struct kobject *kobj, static struct kobj_attribute hpage_pmd_size_attr = __ATTR_RO(hpage_pmd_size); +static ssize_t split_underutilized_thp_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%d\n", split_underutilized_thp); +} + +static ssize_t split_underutilized_thp_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err = kstrtobool(buf, &split_underutilized_thp); + + if (err < 0) + return err; + + return count; +} + +static struct kobj_attribute split_underutilized_thp_attr = __ATTR( + thp_low_util_shrinker, 0644, split_underutilized_thp_show, split_underutilized_thp_store); + static struct attribute *hugepage_attr[] = { &enabled_attr.attr, &defrag_attr.attr, @@ -447,6 +469,7 @@ static struct attribute *hugepage_attr[] = { #ifdef CONFIG_SHMEM &shmem_enabled_attr.attr, #endif + &split_underutilized_thp_attr.attr, NULL, }; @@ -3475,6 +3498,9 @@ void deferred_split_folio(struct folio *folio, bool partially_mapped) if (folio_order(folio) <= 1) return; + if (!partially_mapped && !split_underutilized_thp) + return; + /* * The try_to_unmap() in page reclaim path might reach here too, * this may cause a race condition to corrupt deferred split queue. -- 2.43.5