From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 42A446281F; Tue, 23 Jan 2024 16:19:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706026760; cv=none; b=q+feC5LvqDJDadZyXqsBl3vdfr1t8kYsmIXKD6p5lc4KQOp/n/twVr81N6RXpWP33JDWBdSB/s3gsfN53VcuhsbuEFAD25fOOs4F/C81bhQkQYtUoapZdtxF7VeAHfvMFg0be27SgFYGU6JIs7fv+1dc5BeZ4eTB0O7jKzIQm3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706026760; c=relaxed/simple; bh=/ApKXRNT1KVzfZ6kukPu6+bsMy5rMlGsIXDqu39eeD0=; h=Content-Type:To:Cc:Subject:References:Date:MIME-Version:From: Message-ID:In-Reply-To; b=LJud2HBqPv4ydoSrakrUPjIiE1TWPfOMbLEF8FxES0CeJoQD5mCXFK7C6ktNbdtMJ3ord5jFh09v0rg4thpqj1LoSKe2iCDfIXjVICGBRtqzARDCkBVEG2/WEBahIxPuvKaLQHTuTXjBVLBrWUS9degV8AUAfjmhBgKQFjxvYSU= 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=SB7sFiAG; arc=none smtp.client-ip=192.198.163.8 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="SB7sFiAG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706026758; x=1737562758; h=to:cc:subject:references:date:mime-version: content-transfer-encoding:from:message-id:in-reply-to; bh=/ApKXRNT1KVzfZ6kukPu6+bsMy5rMlGsIXDqu39eeD0=; b=SB7sFiAGg2GIzzEjnxSQT/Wbv3WaQhF3gTN9j48AZG7Z9sN8UOpPfPcQ MNZo8y8EeJcUl9bbf6dz/jLy3rxuXOCNmJSGhdh3bGI8d1sTr+kmigTom u4To5fIQj3t4vMB/yikFB1xz5hWDXr5XFPXtwH88XcS7TQb4xdHMNWmfF +tIWcHqxxrTzTGmcmwFzgpeX90vvm6EC36lnfrAMG6MgsifD1eYptvHhM wgJ2uk97X0LJv9OTWfOOQ6B041IvI13ncvrPiqayyL8Gzy80HZdbLcEg6 BlXlIQOrICXzdzxCZrb8fGLGMDF4jCygJMOrVgKIk2NNRIJnIDVbGOqJg w==; X-IronPort-AV: E=McAfee;i="6600,9927,10962"; a="15086993" X-IronPort-AV: E=Sophos;i="6.05,214,1701158400"; d="scan'208";a="15086993" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2024 08:19:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,214,1701158400"; d="scan'208";a="34455278" Received: from hhuan26-mobl.amr.corp.intel.com ([10.92.17.168]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 23 Jan 2024 08:19:15 -0800 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes To: dave.hansen@linux.intel.com, tj@kernel.org, mkoutny@suse.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, "Jarkko Sakkinen" 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: Re: [PATCH v7 01/15] cgroup/misc: Add per resource callbacks for CSS events References: <20240122172048.11953-1-haitao.huang@linux.intel.com> <20240122172048.11953-2-haitao.huang@linux.intel.com> Date: Tue, 23 Jan 2024 10:19:11 -0600 Precedence: bulk X-Mailing-List: linux-sgx@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Haitao Huang" Organization: Intel Message-ID: In-Reply-To: User-Agent: Opera Mail/1.0 (Win32) On Mon, 22 Jan 2024 14:14:01 -0600, Jarkko Sakkinen wrote: > On Mon Jan 22, 2024 at 7:20 PM EET, Haitao Huang wrote: >> 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. >> >> 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. >> >> Signed-off-by: Kristen Carlson Accardi >> Co-developed-by: Haitao Huang >> Signed-off-by: Haitao Huang >> --- >> V7: >> - Make ops one per resource type and store them in array (Michal) >> - Rename the ops struct to misc_res_ops, and enforce the constraints of >> required callback >> functions (Jarkko) >> - Moved addition of priv field to patch 4 where it was used first. >> (Jarkko) >> >> V6: >> - Create ops struct for per resource callbacks (Jarkko) >> - Drop max_write callback (Dave, Michal) >> - Style fixes (Kai) >> --- >> include/linux/misc_cgroup.h | 11 +++++++ >> kernel/cgroup/misc.c | 60 +++++++++++++++++++++++++++++++++++-- >> 2 files changed, 68 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h >> index e799b1f8d05b..0806d4436208 100644 >> --- a/include/linux/misc_cgroup.h >> +++ b/include/linux/misc_cgroup.h >> @@ -27,6 +27,16 @@ struct misc_cg; >> >> #include >> >> +/** >> + * struct misc_res_ops: per resource type callback ops. >> + * @alloc: invoked for resource specific initialization when cgroup is >> allocated. >> + * @free: invoked for resource specific cleanup when cgroup is >> deallocated. >> + */ >> +struct misc_res_ops { >> + int (*alloc)(struct misc_cg *cg); >> + void (*free)(struct misc_cg *cg); >> +}; >> + >> /** >> * struct misc_res: Per cgroup per misc type resource >> * @max: Maximum limit on the resource. >> @@ -56,6 +66,7 @@ struct misc_cg { >> >> u64 misc_cg_res_total_usage(enum misc_res_type type); >> int misc_cg_set_capacity(enum misc_res_type type, u64 capacity); >> +int misc_cg_set_ops(enum misc_res_type type, const struct misc_res_ops >> *ops); >> int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, >> u64 amount); >> void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg, u64 >> amount); >> >> diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c >> index 79a3717a5803..b8c32791334c 100644 >> --- a/kernel/cgroup/misc.c >> +++ b/kernel/cgroup/misc.c >> @@ -39,6 +39,9 @@ static struct misc_cg root_cg; >> */ >> static u64 misc_res_capacity[MISC_CG_RES_TYPES]; >> >> +/* Resource type specific operations */ >> +static const struct misc_res_ops *misc_res_ops[MISC_CG_RES_TYPES]; >> + >> /** >> * parent_misc() - Get the parent of the passed misc cgroup. >> * @cgroup: cgroup whose parent needs to be fetched. >> @@ -105,6 +108,36 @@ int misc_cg_set_capacity(enum misc_res_type type, >> u64 capacity) >> } >> EXPORT_SYMBOL_GPL(misc_cg_set_capacity); >> >> +/** >> + * misc_cg_set_ops() - set resource specific operations. >> + * @type: Type of the misc res. >> + * @ops: Operations for the given type. >> + * >> + * Context: Any context. >> + * Return: >> + * * %0 - Successfully registered the operations. >> + * * %-EINVAL - If @type is invalid, or the operations missing any >> required callbacks. >> + */ >> +int misc_cg_set_ops(enum misc_res_type type, const struct misc_res_ops >> *ops) >> +{ >> + if (!valid_type(type)) >> + return -EINVAL; >> + >> + if (!ops->alloc) { >> + pr_err("%s: alloc missing\n", __func__); >> + return -EINVAL; >> + } >> + >> + if (!ops->free) { >> + pr_err("%s: free missing\n", __func__); >> + return -EINVAL; >> + } >> + >> + misc_res_ops[type] = ops; >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(misc_cg_set_ops); >> + >> /** >> * misc_cg_cancel_charge() - Cancel the charge from the misc cgroup. >> * @type: Misc res type in misc cg to cancel the charge from. >> @@ -383,23 +416,37 @@ 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, *cg; >> enum misc_res_type i; >> - struct misc_cg *cg; >> + int ret; >> >> if (!parent_css) { >> - cg = &root_cg; >> + parent_cg = 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 (misc_res_ops[i]) { >> + ret = misc_res_ops[i]->alloc(cg); >> + if (ret) >> + goto alloc_err; > > So I'd consider pattern like this to avoid repetition: > > if (ret) { > __misc_cg_free(cg); > return PERR_PTR(ret); > } > > and call __misc_cg_free() also in misc_cg_free(). > Will change to do that. Thanks Haitao