From patchwork Fri Aug 30 16:40:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13785350 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B8691BCA1E; Fri, 30 Aug 2024 16:41:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725036102; cv=none; b=mqb7IlaNoaf2AHltTTT5fYnUc2MQ8bRccoT246o3iXhUSrAf8s1waicdU70VIDbAYsdX/SwKNmTV0CotPuV5+UPRbqoYvToi9N63JE4xEkRXkqpzuoTTuS1M1XWQnXziuD5j4093hAWO1iSyx/bD3H/oAHgPSf1MhdKIwJ+rosY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725036102; c=relaxed/simple; bh=YUKariCmlfVCxX2JHHjkResiD6JNgD6M4hXa3h5e0FA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GtOdFBwmDtNgQN4z3OyzbFEeEBjNnS01OR/oK3azf8EKdF6DyJhUI9bp6prr4PtfrAbRNELSuDkyoyTIroTCcoLwQsGjPSfaFYQD2/k4zVrEmoXEsZUvnaKr7EC/i2BJ7s2zynTdAlE3JRP2+pi2L6dosArRQ1Y41swN4t4KW/0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=C59t0xkK; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="C59t0xkK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1725036100; x=1756572100; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YUKariCmlfVCxX2JHHjkResiD6JNgD6M4hXa3h5e0FA=; b=C59t0xkKda7/iFfllRmr6u0FAlecNN3oof9PohTuulQnVXqKyrv3nFiq +mCEe+SPG0LmVUCORALN5rBc1bEMYT3yYD7QD4XT6Cw1FfQoKxnP+MUyL Ul+hzT8UArfK627/9wR/tXdcU9PC7QlciSI5AM6tw7+k959Dhg10CrH/g YtyRC3EIYb7H3kaqLHTEgRv1BGPwvkxVaD5YA9rniytmys+k5nXOavxSE XcMXatmYyiATqUO/hhgO5AVTH909+yoUUBklgQ3i1L39CgRewE0WaCpKr EzppeGeR/z4hb3LTto3ujiPqioxGT3iiUbrA74Qq5ol2fmxE8Flws0p9v g==; X-CSE-ConnectionGUID: bPNPjF2OSoC/phbSeVDeOQ== X-CSE-MsgGUID: LkVxBFFkRLKTS1JGPoyXlg== X-IronPort-AV: E=McAfee;i="6700,10204,11180"; a="34300029" X-IronPort-AV: E=Sophos;i="6.10,189,1719903600"; d="scan'208";a="34300029" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2024 09:40:52 -0700 X-CSE-ConnectionGUID: kFxoRvDKQlqtdLTpIGtf4g== X-CSE-MsgGUID: w/LfNAl2RnmoZVGifFjhzg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,189,1719903600"; d="scan'208";a="101440491" Received: from b4969164b36c.jf.intel.com ([10.165.59.5]) by orviesa001.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2024 09:40:53 -0700 From: Haitao Huang To: jarkko@kernel.org, dave.hansen@linux.intel.com, kai.huang@intel.com, tj@kernel.org, mkoutny@suse.com, chenridong@huawei.com, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, x86@kernel.org, cgroups@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sohil.mehta@intel.com, tim.c.chen@linux.intel.com Cc: zhiquan1.li@intel.com, kristen@linux.intel.com, seanjc@google.com, zhanb@microsoft.com, anakrish@microsoft.com, mikko.ylinen@linux.intel.com, yangjie@microsoft.com, chrisyan@microsoft.com Subject: [PATCH v17 13/16] x86/sgx: Revise global reclamation for EPC cgroups Date: Fri, 30 Aug 2024 09:40:34 -0700 Message-ID: <20240830164038.39343-14-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240830164038.39343-1-haitao.huang@linux.intel.com> References: <20240830164038.39343-1-haitao.huang@linux.intel.com> Precedence: bulk X-Mailing-List: linux-sgx@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 With EPC cgroups, the global reclamation function, sgx_reclaim_pages_global(), can no longer apply to the global LRU as pages are now in per-cgroup LRUs. Create a wrapper, sgx_cgroup_reclaim_global() to invoke sgx_cgroup_reclaim_pages() passing in the root cgroup. The wrapper will scan and attempt to reclaim SGX_NR_TO_SCAN pages just like the current global reclaim. Note this simple implementation doesn't _exactly_ mimic the current global EPC reclaim (which always tries to do the actual reclaim in batch of SGX_NR_TO_SCAN pages): in rare cases when LRUs have less than SGX_NR_TO_SCAN reclaimable pages, the actual reclaim of EPC pages will be split into smaller batches _across_ multiple LRUs with each being smaller than SGX_NR_TO_SCAN pages. A more precise way to mimic the current global EPC reclaim would be to have a new function to only "scan" (or "isolate") SGX_NR_TO_SCAN pages _across_ the given EPC cgroup _AND_ its descendants, and then do the actual reclaim in one batch. But this is unnecessarily complicated at this stage to address such rare cases. Signed-off-by: Haitao Huang Reviewed-by: Kai Huang Reviewed-by: Jarkko Sakkinen --- V17: - Add comments in sgx_can_reclaim_global(). (Kai) - Remove inaccurate comments in commit msg. (Kai) --- arch/x86/kernel/cpu/sgx/epc_cgroup.c | 12 ++++++++++++ arch/x86/kernel/cpu/sgx/epc_cgroup.h | 2 ++ arch/x86/kernel/cpu/sgx/main.c | 14 ++++++++++++++ 3 files changed, 28 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/epc_cgroup.c b/arch/x86/kernel/cpu/sgx/epc_cgroup.c index 7394f78dec49..c85ec1a6ebf0 100644 --- a/arch/x86/kernel/cpu/sgx/epc_cgroup.c +++ b/arch/x86/kernel/cpu/sgx/epc_cgroup.c @@ -255,6 +255,18 @@ void sgx_cgroup_reclaim_direct(void) sgx_put_cg(sgx_cg); } +/** + * sgx_cgroup_reclaim_pages_global() - Perform one round of global reclamation. + * + * @charge_mm: The mm to be charged for the backing store of reclaimed pages. + * + * Try to scan and attempt reclamation from root cgroup for %SGX_NR_TO_SCAN pages. + */ +void sgx_cgroup_reclaim_pages_global(struct mm_struct *charge_mm) +{ + sgx_cgroup_reclaim_pages(&sgx_cg_root, charge_mm, SGX_NR_TO_SCAN); +} + /* * Asynchronous work flow to reclaim pages from the cgroup when the cgroup is * at/near its maximum capacity. diff --git a/arch/x86/kernel/cpu/sgx/epc_cgroup.h b/arch/x86/kernel/cpu/sgx/epc_cgroup.h index a530c9611332..08cee70d975d 100644 --- a/arch/x86/kernel/cpu/sgx/epc_cgroup.h +++ b/arch/x86/kernel/cpu/sgx/epc_cgroup.h @@ -36,6 +36,7 @@ static inline int __init sgx_cgroup_wq_init(void) static inline void __init sgx_cgroup_wq_deinit(void) { } static inline void sgx_cgroup_reclaim_direct(void) { } +static inline void sgx_cgroup_reclaim_pages_global(struct mm_struct *charge_mm) { } #else /* CONFIG_CGROUP_MISC */ @@ -89,6 +90,7 @@ static inline void sgx_put_cg(struct sgx_cgroup *sgx_cg) int sgx_cgroup_try_charge(struct sgx_cgroup *sgx_cg, enum sgx_reclaim reclaim); void sgx_cgroup_uncharge(struct sgx_cgroup *sgx_cg); void sgx_cgroup_reclaim_direct(void); +void sgx_cgroup_reclaim_pages_global(struct mm_struct *charge_mm); void __init sgx_cgroup_init(void); int __init sgx_cgroup_wq_init(void); void __init sgx_cgroup_wq_deinit(void); diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 6f293115b75e..24dbcbc0f596 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -42,6 +42,13 @@ static inline struct sgx_epc_lru_list *sgx_epc_page_lru(struct sgx_epc_page *epc */ static inline bool sgx_can_reclaim_global(void) { + /* + * Now all EPC pages are still tracked in the @sgx_global_lru, so only + * check @sgx_global_lru. + * + * When EPC pages are tracked in the actual per-cgroup LRUs, + * replace with sgx_cgroup_lru_empty(misc_cg_root()). + */ return !list_empty(&sgx_global_lru.reclaimable); } @@ -404,6 +411,13 @@ static bool sgx_should_reclaim_global(unsigned long watermark) static void sgx_reclaim_pages_global(struct mm_struct *charge_mm) { + /* + * Now all EPC pages are still tracked in the @sgx_global_lru. + * Still reclaim from it. + * + * When EPC pages are tracked in the actual per-cgroup LRUs, + * sgx_cgroup_reclaim_pages_global() will be called. + */ sgx_reclaim_pages(&sgx_global_lru, charge_mm); }