Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757331Ab2HNSwR (ORCPT ); Tue, 14 Aug 2012 14:52:17 -0400 Received: from usindpps03.hds.com ([207.126.252.16]:47709 "EHLO usindpps03.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756069Ab2HNSwQ convert rfc822-to-8bit (ORCPT ); Tue, 14 Aug 2012 14:52:16 -0400 From: Seiji Aguchi To: Mike Waychison CC: "linux-kernel@vger.kernel.org" , "Luck, Tony (tony.luck@intel.com)" , "Matthew Garrett (mjg@redhat.com)" , "dzickus@redhat.com" , "dle-develop@lists.sourceforge.net" , Satoru Moriya Subject: RE: efi_pstore: question about how to remove create_sysfs_entry() from a write callback. Thread-Topic: efi_pstore: question about how to remove create_sysfs_entry() from a write callback. Thread-Index: Ac16Npmt6jTfpP4+SGO2J5V3Hs4KkwAMhuYAAAddZ3A= Date: Tue, 14 Aug 2012 18:51:59 +0000 Message-ID: References: In-Reply-To: Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.74.43.113] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.7.7855,1.0.260,0.0.0000 definitions=2012-08-14_04:2012-08-14,2012-08-14,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_policy_notspam policy=outbound_policy score=0 spamscore=0 ipscore=0 suspectscore=1 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1203120001 definitions=main-1208140184 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 910 Lines: 28 > Can we not serialize this with &efivars->lock if it is updated to disable interrupts? A loop in the workqueue that locks, iterates through > ->get_next_variable, and compares against searches in > efivars->list should work, no? If my understanding is correct, your pseudo code is as follows. spin_lock_irqsave(&efivars_lock); do { get_next_variable(); if (found new entry) efivars_create_sysfs_entries(); } while() spin_lock_irqrestore(&efivars_lock); But, memory is allocated dynamically with kzalloc() in efivars_create_sysfs_entries(). I don't want to allocate memory while holding spin_lock. Please let me know if I'm missing something. Seiji -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/