Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756375Ab2FJKuP (ORCPT ); Sun, 10 Jun 2012 06:50:15 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:64361 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756206Ab2FJKuJ (ORCPT ); Sun, 10 Jun 2012 06:50:09 -0400 From: Sasha Levin To: dan.magenheimer@oracle.com, konrad.wilk@oracle.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sasha Levin Subject: [PATCH v3 04/10] mm: frontswap: split out __frontswap_unuse_pages Date: Sun, 10 Jun 2012 12:51:02 +0200 Message-Id: <1339325468-30614-5-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1339325468-30614-1-git-send-email-levinsasha928@gmail.com> References: <1339325468-30614-1-git-send-email-levinsasha928@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3320 Lines: 105 An attempt at making frontswap_shrink shorter and more readable. This patch splits out walking through the swap list to find an entry with enough pages to unuse. Also, assert that the internal __frontswap_unuse_pages is called under swap lock, since that part of code was previously directly happen inside the lock. Signed-off-by: Sasha Levin --- mm/frontswap.c | 59 +++++++++++++++++++++++++++++++++++++------------------- 1 files changed, 39 insertions(+), 20 deletions(-) diff --git a/mm/frontswap.c b/mm/frontswap.c index 5faf840..faa43b7 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -230,6 +230,41 @@ static unsigned long __frontswap_curr_pages(void) return totalpages; } +static int __frontswap_unuse_pages(unsigned long total, unsigned long *unused, + int *swapid) +{ + int ret = -EINVAL; + struct swap_info_struct *si = NULL; + int si_frontswap_pages; + unsigned long total_pages_to_unuse = total; + unsigned long pages = 0, pages_to_unuse = 0; + int type; + + assert_spin_locked(&swap_lock); + for (type = swap_list.head; type >= 0; type = si->next) { + si = swap_info[type]; + si_frontswap_pages = atomic_read(&si->frontswap_pages); + if (total_pages_to_unuse < si_frontswap_pages) { + pages = pages_to_unuse = total_pages_to_unuse; + } else { + pages = si_frontswap_pages; + pages_to_unuse = 0; /* unuse all */ + } + /* ensure there is enough RAM to fetch pages from frontswap */ + if (security_vm_enough_memory_mm(current->mm, pages)) { + ret = -ENOMEM; + continue; + } + vm_unacct_memory(pages); + *unused = pages_to_unuse; + *swapid = type; + ret = 0; + break; + } + + return ret; +} + /* * Frontswap, like a true swap device, may unnecessarily retain pages * under certain circumstances; "shrink" frontswap is essentially a @@ -240,11 +275,9 @@ static unsigned long __frontswap_curr_pages(void) */ void frontswap_shrink(unsigned long target_pages) { - struct swap_info_struct *si = NULL; - int si_frontswap_pages; unsigned long total_pages = 0, total_pages_to_unuse; - unsigned long pages = 0, pages_to_unuse = 0; - int type; + unsigned long pages_to_unuse = 0; + int type, ret; bool locked = false; /* @@ -258,22 +291,8 @@ void frontswap_shrink(unsigned long target_pages) if (total_pages <= target_pages) goto out; total_pages_to_unuse = total_pages - target_pages; - for (type = swap_list.head; type >= 0; type = si->next) { - si = swap_info[type]; - si_frontswap_pages = atomic_read(&si->frontswap_pages); - if (total_pages_to_unuse < si_frontswap_pages) { - pages = pages_to_unuse = total_pages_to_unuse; - } else { - pages = si_frontswap_pages; - pages_to_unuse = 0; /* unuse all */ - } - /* ensure there is enough RAM to fetch pages from frontswap */ - if (security_vm_enough_memory_mm(current->mm, pages)) - continue; - vm_unacct_memory(pages); - break; - } - if (type < 0) + ret = __frontswap_unuse_pages(total_pages_to_unuse, &pages_to_unuse, &type); + if (ret < 0) goto out; locked = false; spin_unlock(&swap_lock); -- 1.7.8.6 -- 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/