From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754855Ab3AKCa2 (ORCPT ); Thu, 10 Jan 2013 21:30:28 -0500 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:45898 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753417Ab3AKCaG (ORCPT ); Thu, 10 Jan 2013 21:30:06 -0500 X-AuditID: 9c930179-b7c7fae00000255c-0e-50ef792a0d6f From: Minchan Kim To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Mel Gorman , Andy Whitcroft , Alexander Nyberg , Randy Dunlap , Michal Nazarewicz Subject: [PATCH v2 2/2] Enhance read_block of page_owner.c Date: Fri, 11 Jan 2013 11:30:01 +0900 Message-Id: <1357871401-7075-2-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1357871401-7075-1-git-send-email-minchan@kernel.org> References: <1357871401-7075-1-git-send-email-minchan@kernel.org> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The read_block reads char one by one until meeting two newline. It's not good for the performance and current code isn't good shape for readability. This patch enhances speed and clean up. Cc: Mel Gorman Cc: Andy Whitcroft Cc: Alexander Nyberg Cc: Randy Dunlap Signed-off-by: Michal Nazarewicz Signed-off-by: Minchan Kim --- Documentation/page_owner.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-) diff --git a/Documentation/page_owner.c b/Documentation/page_owner.c index 43dde96..96bf481 100644 --- a/Documentation/page_owner.c +++ b/Documentation/page_owner.c @@ -28,26 +28,17 @@ static int max_size; struct block_list *block_head; -int read_block(char *buf, FILE *fin) +int read_block(char *buf, int buf_size, FILE *fin) { - int ret = 0; - int hit = 0; - int val; - char *curr = buf; - - for (;;) { - val = getc(fin); - if (val == EOF) return -1; - *curr = val; - ret++; - if (*curr == '\n' && hit == 1) - return ret - 1; - else if (*curr == '\n') - hit = 1; - else - hit = 0; - curr++; + char *curr = buf, *const buf_end = buf + buf_size; + + while (buf_end - curr > 1 && fgets(curr, buf_end - curr, fin)) { + if (*curr == '\n') /* empty line */ + return curr - buf; + curr += strlen(curr); } + + return -1; /* EOF or no space left in buf. */ } static int compare_txt(struct block_list *l1, struct block_list *l2) @@ -84,10 +75,12 @@ static void add_list(char *buf, int len) } } +#define BUF_SIZE 1024 + int main(int argc, char **argv) { FILE *fin, *fout; - char buf[1024]; + char buf[BUF_SIZE]; int ret, i, count; struct block_list *list2; struct stat st; @@ -106,11 +99,10 @@ int main(int argc, char **argv) list = malloc(max_size * sizeof(*list)); for(;;) { - ret = read_block(buf, fin); + ret = read_block(buf, BUF_SIZE, fin); if (ret < 0) break; - buf[ret] = '\0'; add_list(buf, ret); } -- 1.7.9.5