From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047AbdAYQh3 (ORCPT ); Wed, 25 Jan 2017 11:37:29 -0500 Received: from mail-lf0-f65.google.com ([209.85.215.65]:32805 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751404AbdAYQh1 (ORCPT ); Wed, 25 Jan 2017 11:37:27 -0500 MIME-Version: 1.0 In-Reply-To: <20170125002426.GA2234@jagdpanzerIV.localdomain> References: <20170124200259.16191-1-ddstreet@ieee.org> <20170124200259.16191-3-ddstreet@ieee.org> <20170125002426.GA2234@jagdpanzerIV.localdomain> From: Dan Streetman Date: Wed, 25 Jan 2017 11:36:40 -0500 X-Google-Sender-Auth: v188GH6rgJDptmdj60GPezp_vE4 Message-ID: Subject: Re: [PATCH 2/3] zswap: allow initialization at boot without pool To: Sergey Senozhatsky Cc: Linux-MM , Andrew Morton , Seth Jennings , Michal Hocko , Minchan Kim , linux-kernel , Dan Streetman Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 24, 2017 at 7:24 PM, Sergey Senozhatsky wrote: > > just a note, > > On (01/24/17 15:02), Dan Streetman wrote: > [..] >> @@ -692,6 +702,15 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, >> */ >> list_add_tail_rcu(&pool->list, &zswap_pools); >> put_pool = pool; >> + } else if (!zswap_has_pool) { >> + /* if initial pool creation failed, and this pool creation also >> + * failed, maybe both compressor and zpool params were bad. >> + * Allow changing this param, so pool creation will succeed >> + * when the other param is changed. We already verified this >> + * param is ok in the zpool_has_pool() or crypto_has_comp() >> + * checks above. >> + */ >> + ret = param_set_charp(s, kp); >> } >> >> spin_unlock(&zswap_pools_lock); > > looks like there still GFP_KERNEL allocation from atomic section: > param_set_charp()->kmalloc_parameter()->kmalloc(GFP_KERNEL), under > `zswap_pools_lock'. thanks, it looks like the other param_set_charp above this new one has been in the spinlock ever since i added the param callback. I'll send a patch. > > -ss > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f71.google.com (mail-lf0-f71.google.com [209.85.215.71]) by kanga.kvack.org (Postfix) with ESMTP id 000AA6B0038 for ; Wed, 25 Jan 2017 11:37:22 -0500 (EST) Received: by mail-lf0-f71.google.com with SMTP id o12so86659359lfg.7 for ; Wed, 25 Jan 2017 08:37:22 -0800 (PST) Received: from mail-lf0-x241.google.com (mail-lf0-x241.google.com. [2a00:1450:4010:c07::241]) by mx.google.com with ESMTPS id s2si15016365lfg.31.2017.01.25.08.37.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jan 2017 08:37:21 -0800 (PST) Received: by mail-lf0-x241.google.com with SMTP id h65so21559908lfi.3 for ; Wed, 25 Jan 2017 08:37:21 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20170125002426.GA2234@jagdpanzerIV.localdomain> References: <20170124200259.16191-1-ddstreet@ieee.org> <20170124200259.16191-3-ddstreet@ieee.org> <20170125002426.GA2234@jagdpanzerIV.localdomain> From: Dan Streetman Date: Wed, 25 Jan 2017 11:36:40 -0500 Message-ID: Subject: Re: [PATCH 2/3] zswap: allow initialization at boot without pool Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Sergey Senozhatsky Cc: Linux-MM , Andrew Morton , Seth Jennings , Michal Hocko , Minchan Kim , linux-kernel , Dan Streetman On Tue, Jan 24, 2017 at 7:24 PM, Sergey Senozhatsky wrote: > > just a note, > > On (01/24/17 15:02), Dan Streetman wrote: > [..] >> @@ -692,6 +702,15 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, >> */ >> list_add_tail_rcu(&pool->list, &zswap_pools); >> put_pool = pool; >> + } else if (!zswap_has_pool) { >> + /* if initial pool creation failed, and this pool creation also >> + * failed, maybe both compressor and zpool params were bad. >> + * Allow changing this param, so pool creation will succeed >> + * when the other param is changed. We already verified this >> + * param is ok in the zpool_has_pool() or crypto_has_comp() >> + * checks above. >> + */ >> + ret = param_set_charp(s, kp); >> } >> >> spin_unlock(&zswap_pools_lock); > > looks like there still GFP_KERNEL allocation from atomic section: > param_set_charp()->kmalloc_parameter()->kmalloc(GFP_KERNEL), under > `zswap_pools_lock'. thanks, it looks like the other param_set_charp above this new one has been in the spinlock ever since i added the param callback. I'll send a patch. > > -ss > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org