From: Dave Chinner <dchinner@xxxxxxxxxx>
The caller of xlog_write() usually has a close accounting of the
aggregated vector length contained in the log vector chain passed to
xlog_write(). There is no need to iterate the chain to calculate he
length of the data in xlog_write_calculate_len() if the caller is
already iterating that chain to build it.
Passing in the vector length avoids doing an extra chain iteration,
which can be a significant amount of work given that large CIL
commits can have hundreds of thousands of vectors attached to the
chain.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
V2: removed unnecessary update of num_iovecs.
fs/xfs/xfs_log.c | 37 ++++++-------------------------------
fs/xfs/xfs_log_cil.c | 16 +++++++++++-----
fs/xfs/xfs_log_priv.h | 2 +-
3 files changed, 18 insertions(+), 37 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index e849f15e9e04..58f9aafce29e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -864,7 +864,8 @@ xlog_write_unmount_record(
*/
if (log->l_targ != log->l_mp->m_ddev_targp)
blkdev_issue_flush(log->l_targ->bt_bdev);
- return xlog_write(log, &vec, ticket, NULL, NULL, XLOG_UNMOUNT_TRANS);
+ return xlog_write(log, &vec, ticket, NULL, NULL, XLOG_UNMOUNT_TRANS,
+ reg.i_len);
}
/*
@@ -1588,7 +1589,8 @@ xlog_commit_record(
/* account for space used by record data */
ticket->t_curr_res -= reg.i_len;
- error = xlog_write(log, &vec, ticket, lsn, iclog, XLOG_COMMIT_TRANS);
+ error = xlog_write(log, &vec, ticket, lsn, iclog, XLOG_COMMIT_TRANS,
+ reg.i_len);
if (error)
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
return error;
@@ -2108,32 +2110,6 @@ xlog_print_trans(
}
}
-/*
- * Calculate the potential space needed by the log vector. All regions contain
- * their own opheaders and they are accounted for in region space so we don't
- * need to add them to the vector length here.
- */
-static int
-xlog_write_calc_vec_length(
- struct xlog_ticket *ticket,
- struct xfs_log_vec *log_vector,
- uint optype)
-{
- struct xfs_log_vec *lv;
- int len = 0;
- int i;
-
- for (lv = log_vector; lv; lv = lv->lv_next) {
- /* we don't write ordered log vectors */
- if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
- continue;
-
- for (i = 0; i < lv->lv_niovecs; i++)
- len += lv->lv_iovecp[i].i_len;
- }
- return len;
-}
-
static xlog_op_header_t *
xlog_write_setup_ophdr(
struct xlog_op_header *ophdr,
@@ -2296,13 +2272,13 @@ xlog_write(
struct xlog_ticket *ticket,
xfs_lsn_t *start_lsn,
struct xlog_in_core **commit_iclog,
- uint optype)
+ uint optype,
+ uint32_t len)
{
struct xlog_in_core *iclog = NULL;
struct xfs_log_vec *lv = log_vector;
struct xfs_log_iovec *vecp = lv->lv_iovecp;
int index = 0;
- int len;
int partial_copy = 0;
int partial_copy_len = 0;
int contwr = 0;
@@ -2317,7 +2293,6 @@ xlog_write(
xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
}
- len = xlog_write_calc_vec_length(ticket, log_vector, optype);
if (start_lsn)
*start_lsn = 0;
while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 58900171de09..68bec4b81052 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -710,11 +710,12 @@ xlog_cil_build_trans_hdr(
sizeof(struct xfs_trans_header);
hdr->lhdr[1].i_type = XLOG_REG_TYPE_TRANSHDR;
- tic->t_curr_res -= hdr->lhdr[0].i_len + hdr->lhdr[1].i_len;
-
lvhdr->lv_niovecs = 2;
lvhdr->lv_iovecp = &hdr->lhdr[0];
+ lvhdr->lv_bytes = hdr->lhdr[0].i_len + hdr->lhdr[1].i_len;
lvhdr->lv_next = ctx->lv_chain;
+
+ tic->t_curr_res -= lvhdr->lv_bytes;
}
/*
@@ -742,7 +743,8 @@ xlog_cil_push_work(
struct xfs_log_vec *lv;
struct xfs_cil_ctx *new_ctx;
struct xlog_in_core *commit_iclog;
- int num_iovecs;
+ int num_iovecs = 0;
+ int num_bytes = 0;
int error = 0;
struct xlog_cil_trans_hdr thdr;
struct xfs_log_vec lvhdr = { NULL };
@@ -835,7 +837,6 @@ xlog_cil_push_work(
* by the flush lock.
*/
lv = NULL;
- num_iovecs = 0;
while (!list_empty(&cil->xc_cil)) {
struct xfs_log_item *item;
@@ -849,6 +850,10 @@ xlog_cil_push_work(
lv = item->li_lv;
item->li_lv = NULL;
num_iovecs += lv->lv_niovecs;
+
+ /* we don't write ordered log vectors */
+ if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED)
+ num_bytes += lv->lv_bytes;
}
/*
@@ -887,6 +892,7 @@ xlog_cil_push_work(
* transaction header here as it is not accounted for in xlog_write().
*/
xlog_cil_build_trans_hdr(ctx, &thdr, &lvhdr, num_iovecs);
+ num_bytes += lvhdr.lv_bytes;
/*
* Before we format and submit the first iclog, we have to ensure that
@@ -901,7 +907,7 @@ xlog_cil_push_work(
* write head.
*/
error = xlog_write(log, &lvhdr, ctx->ticket, &ctx->start_lsn, NULL,
- XLOG_START_TRANS);
+ XLOG_START_TRANS, num_bytes);
if (error)
goto out_abort_free_ticket;
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 301c36165974..eba905c273b0 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -459,7 +459,7 @@ void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket);
void xlog_print_trans(struct xfs_trans *);
int xlog_write(struct xlog *log, struct xfs_log_vec *log_vector,
struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
- struct xlog_in_core **commit_iclog, uint optype);
+ struct xlog_in_core **commit_iclog, uint optype, uint32_t len);
int xlog_commit_record(struct xlog *log, struct xlog_ticket *ticket,
struct xlog_in_core **iclog, xfs_lsn_t *lsn);
--
Dave Chinner
david@xxxxxxxxxxxxx
