From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dawson Engler Message-Id: <200303221145.h2MBjAW09391@csl.stanford.edu> Subject: [CHECKER] races in 2.5.65/mm/swapfile.c? Date: Sat, 22 Mar 2003 03:45:10 -0800 (PST) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Dawson Engler List-ID: Hi All, mm/swapfile.c seems to have three potential races. The first two are in linux-2.5.62/mm/swap_state.c:87:add_to_swap_cache which seems reachable without a lock from the callchain: mm/swapfile.c:sys_swapoff:998-> sys_swapoff:1026-> try_to_unuse:591-> mm/swap_state.c:read_swap_cache_async:377-> add_to_swap_cache add_to_swap_cache increments two global variables without a lock: INC_CACHE_INFO(add_total); and INC_CACHE_INFO(exist_race); The final one is in linux-2.5.62/mm/swapfile.c:213:swap_entry_free which seems to increment nr_swap_pages++; without a lock. Are these real races? Or are these just stats variables? (Or is there some implicit locking that protects these?) Regards, Dawson -- 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: aart@kvack.org