From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: [PATCH] IDE: Save a call to PageHighMem() Date: Tue, 23 Jun 2009 10:12:39 +0200 Message-ID: <20090623101239.2f510604@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from zone0.gcu-squad.org ([212.85.147.21]:17794 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495AbZFWIMt (ORCPT ); Tue, 23 Jun 2009 04:12:49 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bartlomiej Zolnierkiewicz Cc: linux-ide@vger.kernel.org PageHighMem() isn't cheap so avoid calling it twice on the same page. Signed-off-by: Jean Delvare Cc: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-taskfile.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- linux-2.6.31-pre.orig/drivers/ide/ide-taskfile.c 2009-06-23 09:01:10.000000000 +0200 +++ linux-2.6.31-pre/drivers/ide/ide-taskfile.c 2009-06-23 09:50:33.000000000 +0200 @@ -236,6 +236,7 @@ void ide_pio_bytes(ide_drive_t *drive, s while (len) { unsigned nr_bytes = min(len, cursg->length - cmd->cursg_ofs); + int page_is_high; if (nr_bytes > PAGE_SIZE) nr_bytes = PAGE_SIZE; @@ -247,7 +248,8 @@ void ide_pio_bytes(ide_drive_t *drive, s page = nth_page(page, (offset >> PAGE_SHIFT)); offset %= PAGE_SIZE; - if (PageHighMem(page)) + page_is_high = PageHighMem(page); + if (page_is_high) local_irq_save(flags); buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset; @@ -268,7 +270,7 @@ void ide_pio_bytes(ide_drive_t *drive, s kunmap_atomic(buf, KM_BIO_SRC_IRQ); - if (PageHighMem(page)) + if (page_is_high) local_irq_restore(flags); len -= nr_bytes; -- Jean Delvare