From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH 5/5] libceph: isolate kmap() call in write_partial_msg_pages() Date: Mon, 12 Mar 2012 17:40:30 -0500 Message-ID: <4F5E7B5E.2050400@dreamhost.com> References: <4F5E79C6.6040301@dreamhost.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.hq.newdream.net ([66.33.206.127]:58522 "EHLO mail.hq.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757533Ab2CLWk0 (ORCPT ); Mon, 12 Mar 2012 18:40:26 -0400 Received: from mail.hq.newdream.net (localhost [127.0.0.1]) by mail.hq.newdream.net (Postfix) with ESMTP id CCB8E243A2 for ; Mon, 12 Mar 2012 15:41:00 -0700 (PDT) Received: from [172.22.22.4] (c-71-195-31-37.hsd1.mn.comcast.net [71.195.31.37]) by mail.hq.newdream.net (Postfix) with ESMTPSA id A00812439E for ; Mon, 12 Mar 2012 15:41:00 -0700 (PDT) In-Reply-To: <4F5E79C6.6040301@dreamhost.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org In write_partial_msg_pages(), every case now does an identical call to kmap(page). Instead, just call it once inside the CRC-computing block where it's needed. Move the definition of kaddr inside that block, and make it a (char *) to ensure portable pointer arithmetic. We still don't kunmap() it until after the sendpage() call, in case that also ends up needing to use the mapping. Signed-off-by: Alex Elder --- net/ceph/messenger.c | 13 ++----------- 1 files changed, 2 insertions(+), 11 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 2bf9ab4..f0993af 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -835,7 +835,6 @@ static int write_partial_msg_pages(struct ceph_connection *con) while (data_len > con->out_msg_pos.data_pos) { struct page *page = NULL; - void *kaddr = NULL; int max_write = PAGE_SIZE; int bio_offset = 0; @@ -856,18 +855,12 @@ static int write_partial_msg_pages(struct ceph_connection *con) page = list_first_entry(&msg->trail->head, struct page, lru); - if (do_datacrc) - kaddr = kmap(page); max_write = PAGE_SIZE; } else if (msg->pages) { page = msg->pages[con->out_msg_pos.page]; - if (do_datacrc) - kaddr = kmap(page); } else if (msg->pagelist) { page = list_first_entry(&msg->pagelist->head, struct page, lru); - if (do_datacrc) - kaddr = kmap(page); #ifdef CONFIG_BLOCK } else if (msg->bio) { struct bio_vec *bv; @@ -875,14 +868,10 @@ static int write_partial_msg_pages(struct ceph_connection *con) bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg); page = bv->bv_page; bio_offset = bv->bv_offset; - if (do_datacrc) - kaddr = kmap(page); max_write = bv->bv_len; #endif } else { page = zero_page; - if (do_datacrc) - kaddr = kmap(page); } len = min_t(int, max_write - con->out_msg_pos.page_pos, total_max_write); @@ -891,7 +880,9 @@ static int write_partial_msg_pages(struct ceph_connection *con) void *base; u32 crc; u32 tmpcrc = le32_to_cpu(con->out_msg->footer.data_crc); + char *kaddr; + kaddr = kmap(page); BUG_ON(kaddr == NULL); base = kaddr + con->out_msg_pos.page_pos + bio_offset; crc = crc32c(tmpcrc, base, len); -- 1.7.5.4