From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F635C432C2 for ; Wed, 25 Sep 2019 18:28:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 765A021D7A for ; Wed, 25 Sep 2019 18:28:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408550AbfIYS22 (ORCPT ); Wed, 25 Sep 2019 14:28:28 -0400 Received: from mga11.intel.com ([192.55.52.93]:15056 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408520AbfIYS22 (ORCPT ); Wed, 25 Sep 2019 14:28:28 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Sep 2019 11:28:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,549,1559545200"; d="scan'208";a="273051579" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga001.jf.intel.com with ESMTP; 25 Sep 2019 11:28:27 -0700 Date: Wed, 25 Sep 2019 11:28:27 -0700 From: Sean Christopherson To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org, Shay Katz-zamir , Serge Ayoun Subject: Re: [PATCH v3 13/17] x86/sgx: Introduce sgx_can_reclaim() Message-ID: <20190925182827.GA32372@linux.intel.com> References: <20190916101803.30726-1-jarkko.sakkinen@linux.intel.com> <20190916101803.30726-14-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190916101803.30726-14-jarkko.sakkinen@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Mon, Sep 16, 2019 at 01:17:59PM +0300, Jarkko Sakkinen wrote: > Make sgx_reclaim_evict() idempotennt and rename it to sgx_can_reclaim() and > set SGX_ENCL_PAGE_RECLAIMED in the call site. > > Cc: Sean Christopherson > Cc: Shay Katz-zamir > Cc: Serge Ayoun > Signed-off-by: Jarkko Sakkinen > --- > arch/x86/kernel/cpu/sgx/reclaim.c | 32 +++++++++++++++++-------------- > 1 file changed, 18 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c > index 5a4d44dd02d7..cc3155b61513 100644 > --- a/arch/x86/kernel/cpu/sgx/reclaim.c > +++ b/arch/x86/kernel/cpu/sgx/reclaim.c > @@ -121,7 +121,19 @@ void sgx_mark_page_reclaimable(struct sgx_epc_page *page) > spin_unlock(&sgx_active_page_list_lock); > } > > -static bool sgx_reclaimer_evict(struct sgx_epc_page *epc_page) > +/** > + * sgx_can_reclaim() - Filter out the pages that should not be reclaimed > + * @epc_page: a candidate EPC page > + * > + * Do not reclaim this page if it has been recently accessed by any mm_struct > + * *and* if the enclave is still alive. No need to take the enclave's lock, > + * worst case scenario reclaiming pages from a dead enclave is delayed slightly. > + * A live enclave with a recently accessed page is more common and avoiding lock > + * contention in that case is a boon to performance. > + * > + * Return: true if the page should be reclaimed > + */ > +static bool sgx_can_reclaim(struct sgx_epc_page *epc_page) Belated thought. The param can be 'struct sgx_encl_page *encl_page'. The caller already has the encl_page, and the function only uses the epc_page to retrieve the encl_page.