Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754103Ab3DWUKE (ORCPT ); Tue, 23 Apr 2013 16:10:04 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:13550 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753145Ab3DWUKC (ORCPT ); Tue, 23 Apr 2013 16:10:02 -0400 X-Authority-Analysis: v=2.0 cv=cOZiQyiN c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=NsHJ4KSHTVMA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=meVymXHHAAAA:8 a=F_i-Va4x4dEA:10 a=eCh5-K-8-Ouzj9uygIAA:9 a=QEXdDO2ut3YA:10 a=9J5VuaLb3qoA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1366747800.9609.170.camel@gandalf.local.home> Subject: [PATCH RT] swap: Use unique local lock name for swap_lock From: Steven Rostedt To: LKML , RT Cc: Thomas Gleixner , Mike Galbraith Date: Tue, 23 Apr 2013 16:10:00 -0400 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3384 Lines: 101 >From lib/Kconfig.debug on CONFIG_FORCE_WEAK_PER_CPU: --- s390 and alpha require percpu variables in modules to be defined weak to work around addressing range issue which puts the following two restrictions on percpu variable definitions. 1. percpu symbols must be unique whether static or not 2. percpu variables can't be defined inside a function To ensure that generic code follows the above rules, this option forces all percpu variables to be defined as weak. --- The addition of the local IRQ swap_lock in mm/swap.c broke this config as the name "swap_lock" is used through out the kernel. Just do a "git grep swap_lock" to see, and the new swap_lock is a local lock which defines the swap_lock for per_cpu. The fix was to rename swap_lock to swapvec_lock which keeps it unique. Reported-by: Mike Galbraith Signed-off-by: Steven Rostedt diff --git a/mm/swap.c b/mm/swap.c index 63f42b8..fab8f97 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -42,7 +42,7 @@ static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); static DEFINE_LOCAL_IRQ_LOCK(rotate_lock); -static DEFINE_LOCAL_IRQ_LOCK(swap_lock); +static DEFINE_LOCAL_IRQ_LOCK(swapvec_lock); /* * This path almost never happens for VM activity - pages are normally @@ -407,13 +407,13 @@ static void activate_page_drain(int cpu) void activate_page(struct page *page) { if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { - struct pagevec *pvec = &get_locked_var(swap_lock, + struct pagevec *pvec = &get_locked_var(swapvec_lock, activate_page_pvecs); page_cache_get(page); if (!pagevec_add(pvec, page)) pagevec_lru_move_fn(pvec, __activate_page, NULL); - put_locked_var(swap_lock, activate_page_pvecs); + put_locked_var(swapvec_lock, activate_page_pvecs); } } @@ -461,13 +461,13 @@ EXPORT_SYMBOL(mark_page_accessed); */ void __lru_cache_add(struct page *page, enum lru_list lru) { - struct pagevec *pvec = &get_locked_var(swap_lock, lru_add_pvecs)[lru]; + struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvecs)[lru]; page_cache_get(page); if (!pagevec_space(pvec)) __pagevec_lru_add(pvec, lru); pagevec_add(pvec, page); - put_locked_var(swap_lock, lru_add_pvecs); + put_locked_var(swapvec_lock, lru_add_pvecs); } EXPORT_SYMBOL(__lru_cache_add); @@ -632,19 +632,19 @@ void deactivate_page(struct page *page) return; if (likely(get_page_unless_zero(page))) { - struct pagevec *pvec = &get_locked_var(swap_lock, + struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_deactivate_pvecs); if (!pagevec_add(pvec, page)) pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); - put_locked_var(swap_lock, lru_deactivate_pvecs); + put_locked_var(swapvec_lock, lru_deactivate_pvecs); } } void lru_add_drain(void) { - lru_add_drain_cpu(local_lock_cpu(swap_lock)); - local_unlock_cpu(swap_lock); + lru_add_drain_cpu(local_lock_cpu(swapvec_lock)); + local_unlock_cpu(swapvec_lock); } static void lru_add_drain_per_cpu(struct work_struct *dummy) -- 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/