From patchwork Sat Sep 23 03:06:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13396513 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31E3FCE7A88 for ; Sat, 23 Sep 2023 03:07:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229705AbjIWDHI (ORCPT ); Fri, 22 Sep 2023 23:07:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229660AbjIWDHH (ORCPT ); Fri, 22 Sep 2023 23:07:07 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 470751A5; Fri, 22 Sep 2023 20:07:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695438421; x=1726974421; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=CWaM84xI5mGXkf+aiRiMgd1gKaujRaa2JuPurtwlf8Y=; b=U0B+NtHFKuBLO9I6DNye3WraaZEKf26w14SdDHHA07l1N79BAQ0lGhPb 8PCaWO2jrzXsqtSKx1atOyyIgN6Q51Kaj9me++3ONChEdNEi7Il3ogEZa 747VrJmx8vjHMiiQWA4Xteav+Apb373Qi2vurET8bP042ktzu5i5eHc/a /sO+FhP3xE8niDlcoCKAXOK2h7p9qsFzbCr2vaGXSjO84mmM+rJ+23DZM wBSTYfNs9SZ/+aXTu3JvlL0HcVa71QRKTCu6jy4Tvfj5LdejMn7VF/ngd SmTMiZUnbumSPoXbOQ+fi82kEumAOusjqJWRTAeKRAIay2rRDsd/n6cOQ A==; X-IronPort-AV: E=McAfee;i="6600,9927,10841"; a="447466722" X-IronPort-AV: E=Sophos;i="6.03,169,1694761200"; d="scan'208";a="447466722" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2023 20:06:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10841"; a="891048516" X-IronPort-AV: E=Sophos;i="6.03,169,1694761200"; d="scan'208";a="891048516" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by fmsmga001.fm.intel.com with ESMTP; 22 Sep 2023 20:06:03 -0700 From: Haitao Huang To: jarkko@kernel.org, dave.hansen@linux.intel.com, tj@kernel.org, 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 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 Subject: [PATCH v5 01/18] cgroup/misc: Add per resource callbacks for CSS events Date: Fri, 22 Sep 2023 20:06:40 -0700 Message-Id: <20230923030657.16148-2-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230923030657.16148-1-haitao.huang@linux.intel.com> References: <20230923030657.16148-1-haitao.huang@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Kristen Carlson Accardi The misc cgroup controller (subsystem) currently does not perform resource type specific action for Cgroups Subsystem State (CSS) events: the 'css_alloc' event when a cgroup is created and the 'css_free' event when a cgroup is destroyed, or in event of user writing the max value to the misc.max file to set the usage limit of a specific resource [admin-guide/cgroup-v2.rst, 5-9. Misc]. Define callbacks for those events and allow resource providers to register the callbacks per resource type as needed. This will be utilized later by the EPC misc cgroup support implemented in the SGX driver: - On css_alloc, allocate and initialize necessary structures for EPC reclaiming, e.g., LRU list, work queue, etc. - On css_free, cleanup and free those structures created in alloc. - On max_write, trigger EPC reclaiming if the new limit is at or below current usage. Signed-off-by: Kristen Carlson Accardi Signed-off-by: Haitao Huang --- V5: - Remove prefixes from the callback names (tj) - Update commit message (Jarkko) V4: - Moved this to the front of the series. - Applies on cgroup/for-6.6 with the overflow fix for misc. V3: - Removed the released() callback --- include/linux/misc_cgroup.h | 5 +++++ kernel/cgroup/misc.c | 32 +++++++++++++++++++++++++++++--- 2 files changed, 34 insertions(+), 3 deletions(-) diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h index e799b1f8d05b..96a88822815a 100644 --- a/include/linux/misc_cgroup.h +++ b/include/linux/misc_cgroup.h @@ -37,6 +37,11 @@ struct misc_res { u64 max; atomic64_t usage; atomic64_t events; + + /* per resource callback ops */ + int (*alloc)(struct misc_cg *cg); + void (*free)(struct misc_cg *cg); + void (*max_write)(struct misc_cg *cg); }; /** diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c index 79a3717a5803..62c9198dee21 100644 --- a/kernel/cgroup/misc.c +++ b/kernel/cgroup/misc.c @@ -276,10 +276,13 @@ static ssize_t misc_cg_max_write(struct kernfs_open_file *of, char *buf, cg = css_misc(of_css(of)); - if (READ_ONCE(misc_res_capacity[type])) + if (READ_ONCE(misc_res_capacity[type])) { WRITE_ONCE(cg->res[type].max, max); - else + if (cg->res[type].max_write) + cg->res[type].max_write(cg); + } else { ret = -EINVAL; + } return ret ? ret : nbytes; } @@ -383,23 +386,39 @@ static struct cftype misc_cg_files[] = { static struct cgroup_subsys_state * misc_cg_alloc(struct cgroup_subsys_state *parent_css) { + struct misc_cg *parent_cg; enum misc_res_type i; struct misc_cg *cg; + int ret; if (!parent_css) { cg = &root_cg; + parent_cg = &root_cg; } else { cg = kzalloc(sizeof(*cg), GFP_KERNEL); if (!cg) return ERR_PTR(-ENOMEM); + parent_cg = css_misc(parent_css); } for (i = 0; i < MISC_CG_RES_TYPES; i++) { WRITE_ONCE(cg->res[i].max, MAX_NUM); atomic64_set(&cg->res[i].usage, 0); + if (parent_cg->res[i].alloc) { + ret = parent_cg->res[i].alloc(cg); + if (ret) + goto alloc_err; + } } return &cg->css; + +alloc_err: + for (i = 0; i < MISC_CG_RES_TYPES; i++) + if (parent_cg->res[i].free) + cg->res[i].free(cg); + kfree(cg); + return ERR_PTR(ret); } /** @@ -410,7 +429,14 @@ misc_cg_alloc(struct cgroup_subsys_state *parent_css) */ static void misc_cg_free(struct cgroup_subsys_state *css) { - kfree(css_misc(css)); + struct misc_cg *cg = css_misc(css); + enum misc_res_type i; + + for (i = 0; i < MISC_CG_RES_TYPES; i++) + if (cg->res[i].free) + cg->res[i].free(cg); + + kfree(cg); } /* Cgroup controller callbacks */