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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2C37C6FA82 for ; Fri, 23 Sep 2022 12:37:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231176AbiIWMhY (ORCPT ); Fri, 23 Sep 2022 08:37:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230110AbiIWMhW (ORCPT ); Fri, 23 Sep 2022 08:37:22 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 452FD12870D; Fri, 23 Sep 2022 05:37:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E9E90B82E2A; Fri, 23 Sep 2022 12:37:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C5DDC433C1; Fri, 23 Sep 2022 12:37:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663936638; bh=6ufS71cwq8f+QgKYS3c0Olp77739jrQ+6Uk+8KSx2gI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rBQix+E3G0MhqACZVF5fEWLWcnppHWANoio3N57g52jL6ckZ77Hhr+C6psPtJHo1y imZIMItciRJPvS/iOW8pHOv9/rzRuF7c2amXKeYG5Dn/ci+rjZGsA1iydRTlB2iYwc fU0gjLwN6c9Hz3FlQSJK+qLpMS/WuvDTlLt03WN+Kv40Em+ptYZ5fRWzvg4Qc+bOMy 8fZfXkye4snjBqfgzlSS8FJG9FdsYc3C3OcZvwbsJCv+hNNfVPYCCuusKdzr9TVyYf lQL+eFXlRX44FM/KTVciYro2A0QBgJwDaX/Cg7Xpz4e7cn3b/yhFv63RK6Mc+t856s wcunbZjsiuHzQ== Date: Fri, 23 Sep 2022 15:37:14 +0300 From: Jarkko Sakkinen To: Kristen Carlson Accardi Cc: linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, cgroups@vger.kernel.org, Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Sean Christopherson Subject: Re: [RFC PATCH 01/20] x86/sgx: Call cond_resched() at the end of sgx_reclaim_pages() Message-ID: References: <20220922171057.1236139-1-kristen@linux.intel.com> <20220922171057.1236139-2-kristen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 23, 2022 at 03:35:25PM +0300, Jarkko Sakkinen wrote: > On Fri, Sep 23, 2022 at 03:32:43PM +0300, Jarkko Sakkinen wrote: > > On Thu, Sep 22, 2022 at 10:10:38AM -0700, Kristen Carlson Accardi wrote: > > > From: Sean Christopherson > > > > > > Move the invocation of post-reclaim cond_resched() from the callers of > > > sgx_reclaim_pages() into the reclaim path itself. sgx_reclaim_pages() > > > is always called in a loop and is always followed by a call to > > > cond_resched(). This will hold true for the EPC cgroup as well, which > > > adds even more calls to sgx_reclaim_pages() and thus cond_resched(). > > > > This would be in my opinion better: > > > > " > > In order to avoid repetion of cond_sched() in ksgxd() and > > sgx_alloc_epc_page(), move the call inside sgx_reclaim_pages(). > > > > This will hold true for the EPC cgroup as well, which adds more > > call sites sgx_reclaim_pages(). > > " > > > > This way it is dead obvious and is better description because > > it enumerates the consequences (i.e. call sites). > > Forgot 3rd call site: sgx_reclaim_direct(), which is used by > SGX2 ioctls. The call sites of sgx_reclaim_direct() do not > call cond_resched(). You should address why adding this call > to those flows is fine. Ofc adding a parameter to sgx_reclaim_pages() for cond_resched() call is other option (not emphasising either option). BR, Jarkko