From 0cdf9e60189a87356a865a96dbafc2240af5c91d Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 7 Mar 2012 11:40:08 -0600 Subject: [PATCH] libceph: get rid of zero_page_address There's not a lot of benefit to zero_page_address, which basically holds a mapping of the zero page through the life of the messenger module. Even with our own mapping, the sendpage interface where it's used may need to kmap() it again. It's almost certain to be in low memory anyway. So stop treating the zero page specially in write_partial_msg_pages() and just get rid of zero_page_address entirely. Signed-off-by: Alex Elder Reviewed-by: Sage Weil --- net/ceph/messenger.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index adca1e6537ab..4f1714c4c93b 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -61,7 +61,6 @@ static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN]; static atomic_t addr_str_seq = ATOMIC_INIT(0); static struct page *zero_page; /* used in certain error cases */ -static void *zero_page_address; /* kernel virtual addr of zero_page */ const char *ceph_pr_addr(const struct sockaddr_storage *ss) { @@ -111,9 +110,6 @@ void _ceph_msgr_exit(void) ceph_msgr_wq = NULL; } - BUG_ON(zero_page_address == NULL); - zero_page_address = NULL; - BUG_ON(zero_page == NULL); kunmap(zero_page); page_cache_release(zero_page); @@ -126,9 +122,6 @@ int ceph_msgr_init(void) zero_page = ZERO_PAGE(0); page_cache_get(zero_page); - BUG_ON(zero_page_address != NULL); - zero_page_address = kmap(zero_page); - ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_NON_REENTRANT, 0); if (ceph_msgr_wq) return 0; @@ -889,7 +882,7 @@ static int write_partial_msg_pages(struct ceph_connection *con) } else { page = zero_page; if (do_datacrc) - kaddr = zero_page_address; + kaddr = kmap(page); } len = min_t(int, max_write - con->out_msg_pos.page_pos, total_max_write); @@ -908,7 +901,7 @@ static int write_partial_msg_pages(struct ceph_connection *con) con->out_msg_pos.page_pos + page_shift, len, 1); - if (do_datacrc && kaddr != zero_page_address) + if (do_datacrc) kunmap(page); if (ret <= 0) -- 2.39.5