*/
/*
* This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
*
* lustre/llite/rw.c
*
static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
struct ra_io_arg *ria,
- unsigned long pages, unsigned long min)
+ unsigned long pages,
+ unsigned long pages_min)
{
- struct ll_ra_info *ra = &sbi->ll_ra_info;
- long ret;
+ struct ll_ra_info *ra = &sbi->ll_ra_info;
+ long ret;
+
ENTRY;
- /* If read-ahead pages left are less than 1M, do not do read-ahead,
- * otherwise it will form small read RPC(< 1M), which hurt server
- * performance a lot. */
+ /**
+ * Don't try readahead agreesively if we are limited
+ * LRU pages, otherwise, it could cause deadlock.
+ */
+ pages = min(sbi->ll_cache->ccc_lru_max >> 2, pages);
+
+ /*
+ * If read-ahead pages left are less than 1M, do not do read-ahead,
+ * otherwise it will form small read RPC(< 1M), which hurt server
+ * performance a lot.
+ */
ret = min(ra->ra_max_pages - atomic_read(&ra->ra_cur_pages),
pages);
- if (ret < 0 || ret < min_t(long, PTLRPC_MAX_BRW_PAGES, pages))
- GOTO(out, ret = 0);
+ if (ret < 0 || ret < min_t(long, PTLRPC_MAX_BRW_PAGES, pages))
+ GOTO(out, ret = 0);
if (atomic_add_return(ret, &ra->ra_cur_pages) > ra->ra_max_pages) {
atomic_sub(ret, &ra->ra_cur_pages);
}
out:
- if (ret < min) {
+ if (ret < pages_min) {
/* override ra limit for maximum performance */
- atomic_add(min - ret, &ra->ra_cur_pages);
- ret = min;
+ atomic_add(pages_min - ret, &ra->ra_cur_pages);
+ ret = pages_min;
}
RETURN(ret);
}
-void ll_ra_count_put(struct ll_sb_info *sbi, unsigned long len)
+void ll_ra_count_put(struct ll_sb_info *sbi, unsigned long pages)
{
struct ll_ra_info *ra = &sbi->ll_ra_info;
- atomic_sub(len, &ra->ra_cur_pages);
+ atomic_sub(pages, &ra->ra_cur_pages);
}
static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which)
lprocfs_counter_incr(sbi->ll_ra_stats, which);
}
+static inline bool ll_readahead_enabled(struct ll_sb_info *sbi)
+{
+ return sbi->ll_ra_info.ra_max_pages_per_file > 0 &&
+ sbi->ll_ra_info.ra_max_pages > 0;
+}
+
void ll_ra_stats_inc(struct inode *inode, enum ra_stat which)
{
struct ll_sb_info *sbi = ll_i2sbi(inode);
}
#define RAS_CDEBUG(ras) \
- CDEBUG(D_READA, \
- "lre %lu cr %lu cb %lu ws %lu wl %lu nra %lu rpc %lu " \
- "r %lu csr %lu sf %lu sb %lu sl %lu lr %lu\n", \
- ras->ras_last_read_end, ras->ras_consecutive_requests, \
- ras->ras_consecutive_bytes, ras->ras_window_start, \
- ras->ras_window_len, ras->ras_next_readahead, \
- ras->ras_rpc_size, ras->ras_requests, \
+ CDEBUG(D_READA, \
+ "lre %llu cr %lu cb %llu wsi %lu wp %lu nra %lu rpc %lu " \
+ "r %lu csr %lu so %llu sb %llu sl %llu lr %lu\n", \
+ ras->ras_last_read_end_bytes, ras->ras_consecutive_requests, \
+ ras->ras_consecutive_bytes, ras->ras_window_start_idx, \
+ ras->ras_window_pages, ras->ras_next_readahead_idx, \
+ ras->ras_rpc_pages, ras->ras_requests, \
ras->ras_consecutive_stride_requests, ras->ras_stride_offset, \
ras->ras_stride_bytes, ras->ras_stride_length, \
- ras->ras_async_last_readpage)
+ ras->ras_async_last_readpage_idx)
-static int pos_in_window(unsigned long pos, unsigned long point,
- unsigned long before, unsigned long after)
+static bool pos_in_window(loff_t pos, loff_t point,
+ unsigned long before, unsigned long after)
{
- unsigned long start = point - before, end = point + after;
+ loff_t start = point - before;
+ loff_t end = point + after;
- if (start > point)
- start = 0;
- if (end < point)
- end = ~0;
+ if (start > point)
+ start = 0;
+ if (end < point)
+ end = ~0;
return start <= pos && pos <= end;
}
+enum ll_ra_page_hint {
+ MAYNEED = 0, /* this page possibly accessed soon */
+ WILLNEED /* this page is gurateed to be needed */
+};
+
/**
* Initiates read-ahead of a page with given index.
*
* \retval 0: page was added into \a queue for read ahead.
*/
static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
- struct cl_page_list *queue, pgoff_t index)
+ struct cl_page_list *queue, pgoff_t index,
+ enum ll_ra_page_hint hint)
{
struct cl_object *clob = io->ci_obj;
struct inode *inode = vvp_object_inode(clob);
- struct page *vmpage;
+ struct page *vmpage = NULL;
struct cl_page *page;
struct vvp_page *vpg;
enum ra_stat which = _NR_RA_STAT; /* keep gcc happy */
int rc = 0;
const char *msg = NULL;
+
ENTRY;
- vmpage = grab_cache_page_nowait(inode->i_mapping, index);
- if (vmpage == NULL) {
- which = RA_STAT_FAILED_GRAB_PAGE;
- msg = "g_c_p_n failed";
- GOTO(out, rc = -EBUSY);
+ switch (hint) {
+ case MAYNEED:
+ vmpage = grab_cache_page_nowait(inode->i_mapping, index);
+ if (vmpage == NULL) {
+ which = RA_STAT_FAILED_GRAB_PAGE;
+ msg = "g_c_p_n failed";
+ GOTO(out, rc = -EBUSY);
+ }
+ break;
+ case WILLNEED:
+ vmpage = find_or_create_page(inode->i_mapping, index,
+ GFP_NOFS);
+ if (vmpage == NULL)
+ GOTO(out, rc = -ENOMEM);
+ break;
+ default:
+ /* should not come here */
+ GOTO(out, rc = -EINVAL);
}
-
+
/* Check if vmpage was truncated or reclaimed */
if (vmpage->mapping != inode->i_mapping) {
which = RA_STAT_WRONG_GRAB_PAGE;
cl_page_assume(env, io, page);
vpg = cl2vvp_page(cl_object_page_slice(clob, page));
if (!vpg->vpg_defer_uptodate && !PageUptodate(vmpage)) {
- vpg->vpg_defer_uptodate = 1;
- vpg->vpg_ra_used = 0;
+ if (hint == MAYNEED) {
+ vpg->vpg_defer_uptodate = 1;
+ vpg->vpg_ra_used = 0;
+ }
cl_page_list_add(queue, page);
} else {
/* skip completed pages */
unlock_page(vmpage);
put_page(vmpage);
}
- if (msg != NULL) {
+ if (msg != NULL && hint == MAYNEED) {
ll_ra_stats_inc(inode, which);
CDEBUG(D_READA, "%s\n", msg);
RETURN(rc);
}
-#define RIA_DEBUG(ria) \
- CDEBUG(D_READA, "rs %lu re %lu ro %lu rl %lu rb %lu\n", \
- ria->ria_start, ria->ria_end, ria->ria_stoff, \
+#define RIA_DEBUG(ria) \
+ CDEBUG(D_READA, "rs %lu re %lu ro %llu rl %llu rb %llu\n", \
+ ria->ria_start_idx, ria->ria_end_idx, ria->ria_stoff, \
ria->ria_length, ria->ria_bytes)
static inline int stride_io_mode(struct ll_readahead_state *ras)
return ras->ras_consecutive_stride_requests > 1;
}
-/* The function calculates how much pages will be read in
+/* The function calculates how many bytes will be read in
* [off, off + length], in such stride IO area,
* stride_offset = st_off, stride_lengh = st_len,
* stride_bytes = st_bytes
* = |<----->| + |-------------------------------------| + |---|
* start_left st_bytes * i end_left
*/
-static unsigned long
-stride_byte_count(unsigned long st_off, unsigned long st_len,
- unsigned long st_bytes, unsigned long off,
- unsigned long length)
+static loff_t stride_byte_count(loff_t st_off, loff_t st_len, loff_t st_bytes,
+ loff_t off, loff_t length)
{
- __u64 start = off > st_off ? off - st_off : 0;
- __u64 end = off + length > st_off ? off + length - st_off : 0;
- unsigned long start_left = 0;
- unsigned long end_left = 0;
- unsigned long bytes_count;
+ u64 start = off > st_off ? off - st_off : 0;
+ u64 end = off + length > st_off ? off + length - st_off : 0;
+ u64 start_left;
+ u64 end_left;
+ u64 bytes_count;
- if (st_len == 0 || length == 0 || end == 0)
- return length;
+ if (st_len == 0 || length == 0 || end == 0)
+ return length;
- start_left = do_div(start, st_len);
+ start = div64_u64_rem(start, st_len, &start_left);
if (start_left < st_bytes)
start_left = st_bytes - start_left;
else
start_left = 0;
- end_left = do_div(end, st_len);
+ end = div64_u64_rem(end, st_len, &end_left);
if (end_left > st_bytes)
end_left = st_bytes;
- CDEBUG(D_READA, "start %llu, end %llu start_left %lu end_left %lu\n",
+ CDEBUG(D_READA, "start %llu, end %llu start_left %llu end_left %llu\n",
start, end, start_left, end_left);
if (start == end)
st_bytes * (end - start - 1) + end_left;
CDEBUG(D_READA,
- "st_off %lu, st_len %lu st_bytes %lu off %lu length %lu bytescount %lu\n",
+ "st_off %llu, st_len %llu st_bytes %llu off %llu length %llu bytescount %llu\n",
st_off, st_len, st_bytes, off, length, bytes_count);
return bytes_count;
}
-static int ria_page_count(struct ra_io_arg *ria)
+static unsigned long ria_page_count(struct ra_io_arg *ria)
{
- u64 length_bytes = ria->ria_end >= ria->ria_start ?
- (ria->ria_end - ria->ria_start + 1) << PAGE_SHIFT : 0;
- unsigned int bytes_count, pg_count;
+ loff_t length_bytes = ria->ria_end_idx >= ria->ria_start_idx ?
+ (loff_t)(ria->ria_end_idx -
+ ria->ria_start_idx + 1) << PAGE_SHIFT : 0;
+ loff_t bytes_count;
if (ria->ria_length > ria->ria_bytes && ria->ria_bytes &&
- (ria->ria_length % PAGE_SIZE || ria->ria_bytes % PAGE_SIZE ||
- ria->ria_stoff % PAGE_SIZE)) {
+ (ria->ria_length & ~PAGE_MASK || ria->ria_bytes & ~PAGE_MASK ||
+ ria->ria_stoff & ~PAGE_MASK)) {
/* Over-estimate un-aligned page stride read */
- pg_count = ((ria->ria_bytes + PAGE_SIZE - 1) >>
- PAGE_SHIFT) + 1;
+ unsigned long pg_count = ((ria->ria_bytes +
+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
pg_count *= length_bytes / ria->ria_length + 1;
return pg_count;
}
bytes_count = stride_byte_count(ria->ria_stoff, ria->ria_length,
- ria->ria_bytes, ria->ria_start,
- length_bytes);
+ ria->ria_bytes,
+ (loff_t)ria->ria_start_idx<<PAGE_SHIFT,
+ length_bytes);
return (bytes_count + PAGE_SIZE - 1) >> PAGE_SHIFT;
}
-static unsigned long ras_align(struct ll_readahead_state *ras,
- pgoff_t index, unsigned long *remainder)
+static pgoff_t ras_align(struct ll_readahead_state *ras, pgoff_t index)
{
- unsigned long rem = index % ras->ras_rpc_size;
- if (remainder != NULL)
- *remainder = rem;
- return index - rem;
+ unsigned opt_size = min(ras->ras_window_pages, ras->ras_rpc_pages);
+
+ if (opt_size == 0)
+ opt_size = 1;
+ return index - (index % opt_size);
}
-/*Check whether the index is in the defined ra-window */
-static bool ras_inside_ra_window(unsigned long idx, struct ra_io_arg *ria)
+/* Check whether the index is in the defined ra-window */
+static bool ras_inside_ra_window(pgoff_t idx, struct ra_io_arg *ria)
{
- unsigned long offset;
- unsigned long pos = idx << PAGE_SHIFT;
+ loff_t pos = (loff_t)idx << PAGE_SHIFT;
/* If ria_length == ria_bytes, it means non-stride I/O mode,
* idx should always inside read-ahead window in this case
return true;
if (pos >= ria->ria_stoff) {
- offset = (pos - ria->ria_stoff) % ria->ria_length;
+ u64 offset;
+
+ div64_u64_rem(pos - ria->ria_stoff, ria->ria_length, &offset);
+
if (offset < ria->ria_bytes ||
(ria->ria_length - offset) < PAGE_SIZE)
return true;
- } else if (pos + PAGE_SIZE > ria->ria_stoff)
+ } else if (pos + PAGE_SIZE > ria->ria_stoff) {
return true;
+ }
return false;
}
static unsigned long
ll_read_ahead_pages(const struct lu_env *env, struct cl_io *io,
struct cl_page_list *queue, struct ll_readahead_state *ras,
- struct ra_io_arg *ria, pgoff_t *ra_end)
+ struct ra_io_arg *ria, pgoff_t *ra_end, pgoff_t skip_index)
{
struct cl_read_ahead ra = { 0 };
- int rc = 0, count = 0;
+ /* busy page count is per stride */
+ int rc = 0, count = 0, busy_page_count = 0;
pgoff_t page_idx;
LASSERT(ria != NULL);
RIA_DEBUG(ria);
- for (page_idx = ria->ria_start;
- page_idx <= ria->ria_end && ria->ria_reserved > 0; page_idx++) {
+ for (page_idx = ria->ria_start_idx;
+ page_idx <= ria->ria_end_idx && ria->ria_reserved > 0;
+ page_idx++) {
+ if (skip_index && page_idx == skip_index)
+ continue;
if (ras_inside_ra_window(page_idx, ria)) {
- if (ra.cra_end == 0 || ra.cra_end < page_idx) {
- unsigned long end;
+ if (ra.cra_end_idx == 0 || ra.cra_end_idx < page_idx) {
+ pgoff_t end_idx;
+
+ /*
+ * Do not shrink ria_end_idx at any case until
+ * the minimum end of current read is covered.
+ *
+ * Do not extend read lock accross stripe if
+ * lock contention detected.
+ */
+ if (ra.cra_contention &&
+ page_idx > ria->ria_end_idx_min) {
+ ria->ria_end_idx = *ra_end;
+ break;
+ }
cl_read_ahead_release(env, &ra);
if (rc < 0)
break;
- /* Do not shrink the ria_end at any case until
- * the minimum end of current read is covered.
- * And only shrink the ria_end if the matched
- * LDLM lock doesn't cover more. */
- if (page_idx > ra.cra_end ||
- (ra.cra_contention &&
- page_idx > ria->ria_end_min)) {
- ria->ria_end = ra.cra_end;
+ /*
+ * Only shrink ria_end_idx if the matched
+ * LDLM lock doesn't cover more.
+ */
+ if (page_idx > ra.cra_end_idx) {
+ ria->ria_end_idx = ra.cra_end_idx;
break;
}
CDEBUG(D_READA, "idx: %lu, ra: %lu, rpc: %lu\n",
- page_idx, ra.cra_end, ra.cra_rpc_size);
- LASSERTF(ra.cra_end >= page_idx,
+ page_idx, ra.cra_end_idx,
+ ra.cra_rpc_pages);
+ LASSERTF(ra.cra_end_idx >= page_idx,
"object: %p, indcies %lu / %lu\n",
- io->ci_obj, ra.cra_end, page_idx);
+ io->ci_obj, ra.cra_end_idx, page_idx);
/* update read ahead RPC size.
* NB: it's racy but doesn't matter */
- if (ras->ras_rpc_size != ra.cra_rpc_size &&
- ra.cra_rpc_size > 0)
- ras->ras_rpc_size = ra.cra_rpc_size;
- /* trim it to align with optimal RPC size */
- end = ras_align(ras, ria->ria_end + 1, NULL);
- if (end > 0 && !ria->ria_eof)
- ria->ria_end = end - 1;
- if (ria->ria_end < ria->ria_end_min)
- ria->ria_end = ria->ria_end_min;
+ if (ras->ras_rpc_pages != ra.cra_rpc_pages &&
+ ra.cra_rpc_pages > 0)
+ ras->ras_rpc_pages = ra.cra_rpc_pages;
+ if (!skip_index) {
+ /* trim it to align with optimal RPC size */
+ end_idx = ras_align(ras, ria->ria_end_idx + 1);
+ if (end_idx > 0 && !ria->ria_eof)
+ ria->ria_end_idx = end_idx - 1;
+ }
+ if (ria->ria_end_idx < ria->ria_end_idx_min)
+ ria->ria_end_idx = ria->ria_end_idx_min;
}
- if (page_idx > ria->ria_end)
+ if (page_idx > ria->ria_end_idx)
break;
/* If the page is inside the read-ahead window */
- rc = ll_read_ahead_page(env, io, queue, page_idx);
- if (rc < 0)
+ rc = ll_read_ahead_page(env, io, queue, page_idx,
+ MAYNEED);
+ if (rc < 0 && rc != -EBUSY)
break;
+ if (rc == -EBUSY) {
+ busy_page_count++;
+ CDEBUG(D_READA,
+ "skip busy page: %lu\n", page_idx);
+ /* For page unaligned readahead the first
+ * last pages of each region can be read by
+ * another reader on the same node, and so
+ * may be busy. So only stop for > 2 busy
+ * pages. */
+ if (busy_page_count > 2)
+ break;
+ }
*ra_end = page_idx;
/* Only subtract from reserve & count the page if we
* read-ahead mode, then check whether it should skip
* the stride gap.
*/
- unsigned long offset;
- unsigned long pos = page_idx << PAGE_SHIFT;
+ loff_t pos = (loff_t)page_idx << PAGE_SHIFT;
+ u64 offset;
- offset = (pos - ria->ria_stoff) % ria->ria_length;
+ div64_u64_rem(pos - ria->ria_stoff, ria->ria_length,
+ &offset);
if (offset >= ria->ria_bytes) {
pos += (ria->ria_length - offset);
if ((pos >> PAGE_SHIFT) >= page_idx + 1)
page_idx = (pos >> PAGE_SHIFT) - 1;
+ busy_page_count = 0;
CDEBUG(D_READA,
- "Stride: jump %lu pages to %lu\n",
+ "Stride: jump %llu pages to %lu\n",
ria->ria_length - offset, page_idx);
continue;
}
struct ll_readahead_state *ras;
struct cl_io *io;
struct cl_2queue *queue;
- pgoff_t ra_end = 0;
- unsigned long len, mlen = 0;
+ pgoff_t ra_end_idx = 0;
+ unsigned long pages, pages_min = 0;
struct file *file;
__u64 kms;
int rc;
- unsigned long end_index;
+ pgoff_t eof_index;
+ struct ll_sb_info *sbi;
work = container_of(wq, struct ll_readahead_work,
lrw_readahead_work);
- fd = LUSTRE_FPRIVATE(work->lrw_file);
+ fd = work->lrw_file->private_data;
ras = &fd->fd_ras;
file = work->lrw_file;
inode = file_inode(file);
+ sbi = ll_i2sbi(inode);
env = cl_env_alloc(&refcheck, LCT_NOREF);
if (IS_ERR(env))
ria = &ll_env_info(env)->lti_ria;
memset(ria, 0, sizeof(*ria));
- ria->ria_start = work->lrw_start;
+ ria->ria_start_idx = work->lrw_start_idx;
/* Truncate RA window to end of file */
- end_index = (unsigned long)((kms - 1) >> PAGE_SHIFT);
- if (end_index <= work->lrw_end) {
- work->lrw_end = end_index;
+ eof_index = (pgoff_t)(kms - 1) >> PAGE_SHIFT;
+ if (eof_index <= work->lrw_end_idx) {
+ work->lrw_end_idx = eof_index;
ria->ria_eof = true;
}
- if (work->lrw_end <= work->lrw_start)
+ if (work->lrw_end_idx <= work->lrw_start_idx)
GOTO(out_put_env, rc = 0);
- ria->ria_end = work->lrw_end;
- len = ria->ria_end - ria->ria_start + 1;
- ria->ria_reserved = ll_ra_count_get(ll_i2sbi(inode), ria,
- ria_page_count(ria), mlen);
+ ria->ria_end_idx = work->lrw_end_idx;
+ pages = ria->ria_end_idx - ria->ria_start_idx + 1;
+ ria->ria_reserved = ll_ra_count_get(sbi, ria,
+ ria_page_count(ria), pages_min);
CDEBUG(D_READA,
"async reserved pages: %lu/%lu/%lu, ra_cur %d, ra_max %lu\n",
- ria->ria_reserved, len, mlen,
+ ria->ria_reserved, pages, pages_min,
atomic_read(&ll_i2sbi(inode)->ll_ra_info.ra_cur_pages),
ll_i2sbi(inode)->ll_ra_info.ra_max_pages);
- if (ria->ria_reserved < len) {
+ if (ria->ria_reserved < pages) {
ll_ra_stats_inc(inode, RA_STAT_MAX_IN_FLIGHT);
if (PAGES_TO_MiB(ria->ria_reserved) < 1) {
ll_ra_count_put(ll_i2sbi(inode), ria->ria_reserved);
}
}
- rc = cl_io_rw_init(env, io, CIT_READ, ria->ria_start, len);
+ rc = cl_io_rw_init(env, io, CIT_READ, ria->ria_start_idx, pages);
if (rc)
GOTO(out_put_env, rc);
- vvp_env_io(env)->vui_io_subtype = IO_NORMAL;
+ /* overwrite jobid inited in vvp_io_init() */
+ if (strncmp(ll_i2info(inode)->lli_jobid, work->lrw_jobid,
+ sizeof(work->lrw_jobid)))
+ memcpy(ll_i2info(inode)->lli_jobid, work->lrw_jobid,
+ sizeof(work->lrw_jobid));
+
vvp_env_io(env)->vui_fd = fd;
io->ci_state = CIS_LOCKED;
io->ci_async_readahead = true;
queue = &io->ci_queue;
cl_2queue_init(queue);
- rc = ll_read_ahead_pages(env, io, &queue->c2_qin, ras, ria, &ra_end);
+ rc = ll_read_ahead_pages(env, io, &queue->c2_qin, ras, ria,
+ &ra_end_idx, 0);
if (ria->ria_reserved != 0)
ll_ra_count_put(ll_i2sbi(inode), ria->ria_reserved);
if (queue->c2_qin.pl_nr > 0) {
if (rc == 0)
task_io_account_read(PAGE_SIZE * count);
}
- if (ria->ria_end == ra_end && ra_end == (kms >> PAGE_SHIFT))
+ if (ria->ria_end_idx == ra_end_idx && ra_end_idx == (kms >> PAGE_SHIFT))
ll_ra_stats_inc(inode, RA_STAT_EOF);
- if (ra_end != ria->ria_end)
+ if (ra_end_idx != ria->ria_end_idx)
ll_ra_stats_inc(inode, RA_STAT_FAILED_REACH_END);
/* TODO: discard all pages until page reinit route is implemented */
out_put_env:
cl_env_put(env, &refcheck);
out_free_work:
- if (ra_end > 0)
+ if (ra_end_idx > 0)
ll_ra_stats_inc_sbi(ll_i2sbi(inode), RA_STAT_ASYNC);
+ atomic_dec(&sbi->ll_ra_info.ra_async_inflight);
ll_readahead_work_free(work);
}
static int ll_readahead(const struct lu_env *env, struct cl_io *io,
struct cl_page_list *queue,
struct ll_readahead_state *ras, bool hit,
- struct file *file)
+ struct file *file, pgoff_t skip_index)
{
struct vvp_io *vio = vvp_env_io(env);
struct ll_thread_info *lti = ll_env_info(env);
- unsigned long len, mlen = 0;
- pgoff_t ra_end = 0, start = 0, end = 0;
+ unsigned long pages, pages_min = 0;
+ pgoff_t ra_end_idx = 0, start_idx = 0, end_idx = 0;
struct inode *inode;
struct ra_io_arg *ria = <i->lti_ria;
struct cl_object *clob;
int ret = 0;
__u64 kms;
+ struct ll_sb_info *sbi;
+ struct ll_ra_info *ra;
+
ENTRY;
+ ENTRY;
+
clob = io->ci_obj;
inode = vvp_object_inode(clob);
+ sbi = ll_i2sbi(inode);
+ ra = &sbi->ll_ra_info;
- memset(ria, 0, sizeof *ria);
+ /**
+ * In case we have a limited max_cached_mb, readahead
+ * should be stopped if it have run out of all LRU slots.
+ */
+ if (atomic_read(&ra->ra_cur_pages) >= sbi->ll_cache->ccc_lru_max) {
+ ll_ra_stats_inc(inode, RA_STAT_MAX_IN_FLIGHT);
+ RETURN(0);
+ }
+
+ memset(ria, 0, sizeof(*ria));
ret = ll_readahead_file_kms(env, io, &kms);
if (ret != 0)
RETURN(ret);
spin_lock(&ras->ras_lock);
/**
- * Note: other thread might rollback the ras_next_readahead,
+ * Note: other thread might rollback the ras_next_readahead_idx,
* if it can not get the full size of prepared pages, see the
* end of this function. For stride read ahead, it needs to
* make sure the offset is no less than ras_stride_offset,
* so that stride read ahead can work correctly.
*/
if (stride_io_mode(ras))
- start = max(ras->ras_next_readahead,
- ras->ras_stride_offset >> PAGE_SHIFT);
+ start_idx = max_t(pgoff_t, ras->ras_next_readahead_idx,
+ ras->ras_stride_offset >> PAGE_SHIFT);
else
- start = ras->ras_next_readahead;
+ start_idx = ras->ras_next_readahead_idx;
+
+ if (ras->ras_window_pages > 0)
+ end_idx = ras->ras_window_start_idx + ras->ras_window_pages - 1;
- if (ras->ras_window_len > 0)
- end = ras->ras_window_start + ras->ras_window_len - 1;
+ if (skip_index)
+ end_idx = start_idx + ras->ras_window_pages - 1;
/* Enlarge the RA window to encompass the full read */
if (vio->vui_ra_valid &&
- end < vio->vui_ra_start + vio->vui_ra_count - 1)
- end = vio->vui_ra_start + vio->vui_ra_count - 1;
+ end_idx < vio->vui_ra_start_idx + vio->vui_ra_pages - 1)
+ end_idx = vio->vui_ra_start_idx + vio->vui_ra_pages - 1;
- if (end != 0) {
- unsigned long end_index;
+ if (end_idx != 0) {
+ pgoff_t eof_index;
/* Truncate RA window to end of file */
- end_index = (unsigned long)((kms - 1) >> PAGE_SHIFT);
- if (end_index <= end) {
- end = end_index;
+ eof_index = (pgoff_t)((kms - 1) >> PAGE_SHIFT);
+ if (eof_index <= end_idx) {
+ end_idx = eof_index;
ria->ria_eof = true;
}
- }
- ria->ria_start = start;
- ria->ria_end = end;
- /* If stride I/O mode is detected, get stride window*/
- if (stride_io_mode(ras)) {
- ria->ria_stoff = ras->ras_stride_offset;
- ria->ria_length = ras->ras_stride_length;
+ }
+ ria->ria_start_idx = start_idx;
+ ria->ria_end_idx = end_idx;
+ /* If stride I/O mode is detected, get stride window*/
+ if (stride_io_mode(ras)) {
+ ria->ria_stoff = ras->ras_stride_offset;
+ ria->ria_length = ras->ras_stride_length;
ria->ria_bytes = ras->ras_stride_bytes;
- }
+ }
spin_unlock(&ras->ras_lock);
- if (end == 0) {
+ if (end_idx == 0) {
ll_ra_stats_inc(inode, RA_STAT_ZERO_WINDOW);
RETURN(0);
}
- len = ria_page_count(ria);
- if (len == 0) {
+ pages = ria_page_count(ria);
+ if (pages == 0) {
ll_ra_stats_inc(inode, RA_STAT_ZERO_WINDOW);
RETURN(0);
}
RAS_CDEBUG(ras);
CDEBUG(D_READA, DFID": ria: %lu/%lu, bead: %lu/%lu, hit: %d\n",
PFID(lu_object_fid(&clob->co_lu)),
- ria->ria_start, ria->ria_end,
- vio->vui_ra_valid ? vio->vui_ra_start : 0,
- vio->vui_ra_valid ? vio->vui_ra_count : 0,
+ ria->ria_start_idx, ria->ria_end_idx,
+ vio->vui_ra_valid ? vio->vui_ra_start_idx : 0,
+ vio->vui_ra_valid ? vio->vui_ra_pages : 0,
hit);
/* at least to extend the readahead window to cover current read */
if (!hit && vio->vui_ra_valid &&
- vio->vui_ra_start + vio->vui_ra_count > ria->ria_start)
- ria->ria_end_min = vio->vui_ra_start + vio->vui_ra_count - 1;
+ vio->vui_ra_start_idx + vio->vui_ra_pages > ria->ria_start_idx) {
+ ria->ria_end_idx_min =
+ vio->vui_ra_start_idx + vio->vui_ra_pages - 1;
+ pages_min = vio->vui_ra_start_idx + vio->vui_ra_pages -
+ ria->ria_start_idx;
+ /**
+ * For performance reason, exceeding @ra_max_pages
+ * are allowed, but this should be limited with RPC
+ * size in case a large block size read issued. Trim
+ * to RPC boundary.
+ */
+ pages_min = min(pages_min, ras->ras_rpc_pages -
+ (ria->ria_start_idx % ras->ras_rpc_pages));
+ }
+
+ /* don't over reserved for mmap range read */
+ if (skip_index)
+ pages_min = 0;
- ria->ria_reserved = ll_ra_count_get(ll_i2sbi(inode), ria, len, mlen);
- if (ria->ria_reserved < len)
+ ria->ria_reserved = ll_ra_count_get(ll_i2sbi(inode), ria, pages,
+ pages_min);
+ if (ria->ria_reserved < pages)
ll_ra_stats_inc(inode, RA_STAT_MAX_IN_FLIGHT);
CDEBUG(D_READA, "reserved pages: %lu/%lu/%lu, ra_cur %d, ra_max %lu\n",
- ria->ria_reserved, len, mlen,
+ ria->ria_reserved, pages, pages_min,
atomic_read(&ll_i2sbi(inode)->ll_ra_info.ra_cur_pages),
ll_i2sbi(inode)->ll_ra_info.ra_max_pages);
- ret = ll_read_ahead_pages(env, io, queue, ras, ria, &ra_end);
-
+ ret = ll_read_ahead_pages(env, io, queue, ras, ria, &ra_end_idx,
+ skip_index);
if (ria->ria_reserved != 0)
ll_ra_count_put(ll_i2sbi(inode), ria->ria_reserved);
- if (ra_end == end && ra_end == (kms >> PAGE_SHIFT))
+ if (ra_end_idx == end_idx && ra_end_idx == (kms >> PAGE_SHIFT))
ll_ra_stats_inc(inode, RA_STAT_EOF);
- CDEBUG(D_READA, "ra_end = %lu end = %lu stride end = %lu pages = %d\n",
- ra_end, end, ria->ria_end, ret);
+ CDEBUG(D_READA,
+ "ra_end_idx = %lu end_idx = %lu stride end = %lu pages = %d\n",
+ ra_end_idx, end_idx, ria->ria_end_idx, ret);
- if (ra_end != end)
+ if (ra_end_idx != end_idx)
ll_ra_stats_inc(inode, RA_STAT_FAILED_REACH_END);
- if (ra_end > 0) {
+ if (ra_end_idx > 0) {
/* update the ras so that the next read-ahead tries from
* where we left off. */
spin_lock(&ras->ras_lock);
- ras->ras_next_readahead = ra_end + 1;
+ ras->ras_next_readahead_idx = ra_end_idx + 1;
spin_unlock(&ras->ras_lock);
RAS_CDEBUG(ras);
}
RETURN(ret);
}
+static int ll_readpages(const struct lu_env *env, struct cl_io *io,
+ struct cl_page_list *queue,
+ pgoff_t start, pgoff_t end)
+{
+ int ret = 0;
+ __u64 kms;
+ pgoff_t page_idx;
+ int count = 0;
+
+ ENTRY;
+
+ ret = ll_readahead_file_kms(env, io, &kms);
+ if (ret != 0)
+ RETURN(ret);
+
+ if (kms == 0)
+ RETURN(0);
+
+ if (end != 0) {
+ unsigned long end_index;
+
+ end_index = (unsigned long)((kms - 1) >> PAGE_SHIFT);
+ if (end_index <= end)
+ end = end_index;
+ }
+
+ for (page_idx = start; page_idx <= end; page_idx++) {
+ ret= ll_read_ahead_page(env, io, queue, page_idx,
+ WILLNEED);
+ if (ret < 0)
+ break;
+ else if (ret == 0) /* ret 1 is already uptodate */
+ count++;
+ }
+
+ RETURN(count > 0 ? count : ret);
+}
+
static void ras_set_start(struct ll_readahead_state *ras, pgoff_t index)
{
- ras->ras_window_start = ras_align(ras, index, NULL);
+ ras->ras_window_start_idx = ras_align(ras, index);
}
/* called with the ras_lock held or from places where it doesn't matter */
{
ras->ras_consecutive_requests = 0;
ras->ras_consecutive_bytes = 0;
- ras->ras_window_len = 0;
+ ras->ras_window_pages = 0;
ras_set_start(ras, index);
- ras->ras_next_readahead = max(ras->ras_window_start, index + 1);
+ ras->ras_next_readahead_idx = max(ras->ras_window_start_idx, index + 1);
RAS_CDEBUG(ras);
}
void ll_readahead_init(struct inode *inode, struct ll_readahead_state *ras)
{
spin_lock_init(&ras->ras_lock);
- ras->ras_rpc_size = PTLRPC_MAX_BRW_PAGES;
+ ras->ras_rpc_pages = PTLRPC_MAX_BRW_PAGES;
ras_reset(ras, 0);
- ras->ras_last_read_end = 0;
+ ras->ras_last_read_end_bytes = 0;
ras->ras_requests = 0;
+ ras->ras_range_min_start_idx = 0;
+ ras->ras_range_max_end_idx = 0;
+ ras->ras_range_requests = 0;
+ ras->ras_last_range_pages = 0;
}
/*
* If it is in the stride window, return true, otherwise return false.
*/
static bool read_in_stride_window(struct ll_readahead_state *ras,
- unsigned long pos, unsigned long count)
+ loff_t pos, loff_t count)
{
- unsigned long stride_gap;
+ loff_t stride_gap;
if (ras->ras_stride_length == 0 || ras->ras_stride_bytes == 0 ||
ras->ras_stride_bytes == ras->ras_stride_length)
return false;
- stride_gap = pos - ras->ras_last_read_end - 1;
+ stride_gap = pos - ras->ras_last_read_end_bytes - 1;
/* If it is contiguous read */
if (stride_gap == 0)
}
static void ras_init_stride_detector(struct ll_readahead_state *ras,
- unsigned long pos, unsigned long count)
+ loff_t pos, loff_t count)
{
- unsigned long stride_gap = pos - ras->ras_last_read_end - 1;
+ loff_t stride_gap = pos - ras->ras_last_read_end_bytes - 1;
LASSERT(ras->ras_consecutive_stride_requests == 0);
- if (pos <= ras->ras_last_read_end) {
+ if (pos <= ras->ras_last_read_end_bytes) {
/*Reset stride window for forward read*/
ras_stride_reset(ras);
return;
}
static unsigned long
-stride_page_count(struct ll_readahead_state *ras, unsigned long len)
+stride_page_count(struct ll_readahead_state *ras, loff_t len)
{
- unsigned int bytes_count =
+ loff_t bytes_count =
stride_byte_count(ras->ras_stride_offset,
ras->ras_stride_length, ras->ras_stride_bytes,
- ras->ras_stride_offset, len);
+ ras->ras_window_start_idx << PAGE_SHIFT, len);
return (bytes_count + PAGE_SIZE - 1) >> PAGE_SHIFT;
}
/* Stride Read-ahead window will be increased inc_len according to
* stride I/O pattern */
static void ras_stride_increase_window(struct ll_readahead_state *ras,
- struct ll_ra_info *ra,
- unsigned long inc_len)
+ struct ll_ra_info *ra, loff_t inc_bytes)
{
- unsigned long left, step, window_len;
- unsigned long stride_len;
- unsigned long end = ras->ras_window_start + ras->ras_window_len;
+ loff_t window_bytes, stride_bytes;
+ u64 left_bytes;
+ u64 step;
+ loff_t end;
- LASSERT(ras->ras_stride_length > 0);
+ /* temporarily store in page units to reduce LASSERT() cost below */
+ end = ras->ras_window_start_idx + ras->ras_window_pages;
+
+ LASSERT(ras->ras_stride_length > 0);
LASSERTF(end >= (ras->ras_stride_offset >> PAGE_SHIFT),
- "window_start %lu, window_len %lu stride_offset %lu\n",
- ras->ras_window_start, ras->ras_window_len,
+ "window_start_idx %lu, window_pages %lu stride_offset %llu\n",
+ ras->ras_window_start_idx, ras->ras_window_pages,
ras->ras_stride_offset);
end <<= PAGE_SHIFT;
- if (end < ras->ras_stride_offset)
- stride_len = 0;
+ if (end <= ras->ras_stride_offset)
+ stride_bytes = 0;
else
- stride_len = end - ras->ras_stride_offset;
-
- left = stride_len % ras->ras_stride_length;
- window_len = (ras->ras_window_len << PAGE_SHIFT) - left;
-
- if (left < ras->ras_stride_bytes)
- left += inc_len;
- else
- left = ras->ras_stride_bytes + inc_len;
+ stride_bytes = end - ras->ras_stride_offset;
+
+ div64_u64_rem(stride_bytes, ras->ras_stride_length, &left_bytes);
+ window_bytes = (ras->ras_window_pages << PAGE_SHIFT);
+ if (left_bytes < ras->ras_stride_bytes) {
+ if (ras->ras_stride_bytes - left_bytes >= inc_bytes) {
+ window_bytes += inc_bytes;
+ goto out;
+ } else {
+ window_bytes += (ras->ras_stride_bytes - left_bytes);
+ inc_bytes -= (ras->ras_stride_bytes - left_bytes);
+ }
+ } else {
+ window_bytes += (ras->ras_stride_length - left_bytes);
+ }
LASSERT(ras->ras_stride_bytes != 0);
- step = left / ras->ras_stride_bytes;
- left %= ras->ras_stride_bytes;
+ step = div64_u64_rem(inc_bytes, ras->ras_stride_bytes, &left_bytes);
- window_len += step * ras->ras_stride_length + left;
+ window_bytes += step * ras->ras_stride_length + left_bytes;
+ LASSERT(window_bytes > 0);
- if (stride_page_count(ras, window_len) <= ra->ra_max_pages_per_file)
- ras->ras_window_len = (window_len >> PAGE_SHIFT);
+out:
+ if (stride_page_count(ras, window_bytes) <=
+ ra->ra_max_pages_per_file || ras->ras_window_pages == 0)
+ ras->ras_window_pages = (window_bytes >> PAGE_SHIFT);
- RAS_CDEBUG(ras);
+ LASSERT(ras->ras_window_pages > 0);
+
+ RAS_CDEBUG(ras);
}
static void ras_increase_window(struct inode *inode,
*/
if (stride_io_mode(ras)) {
ras_stride_increase_window(ras, ra,
- ras->ras_rpc_size << PAGE_SHIFT);
+ (loff_t)ras->ras_rpc_pages << PAGE_SHIFT);
} else {
- unsigned long wlen;
+ pgoff_t window_pages;
- wlen = min(ras->ras_window_len + ras->ras_rpc_size,
- ra->ra_max_pages_per_file);
- if (wlen < ras->ras_rpc_size)
- ras->ras_window_len = wlen;
+ window_pages = min(ras->ras_window_pages + ras->ras_rpc_pages,
+ ra->ra_max_pages_per_file);
+ if (window_pages < ras->ras_rpc_pages)
+ ras->ras_window_pages = window_pages;
else
- ras->ras_window_len = ras_align(ras, wlen, NULL);
+ ras->ras_window_pages = ras_align(ras, window_pages);
}
}
/**
* Seek within 8 pages are considered as sequential read for now.
*/
-static inline bool is_loose_seq_read(struct ll_readahead_state *ras,
- unsigned long pos)
+static inline bool is_loose_seq_read(struct ll_readahead_state *ras, loff_t pos)
{
- return pos_in_window(pos, ras->ras_last_read_end,
- 8 << PAGE_SHIFT, 8 << PAGE_SHIFT);
+ return pos_in_window(pos, ras->ras_last_read_end_bytes,
+ 8UL << PAGE_SHIFT, 8UL << PAGE_SHIFT);
+}
+
+static inline bool is_loose_mmap_read(struct ll_sb_info *sbi,
+ struct ll_readahead_state *ras,
+ unsigned long pos)
+{
+ unsigned long range_pages = sbi->ll_ra_info.ra_range_pages;
+
+ return pos_in_window(pos, ras->ras_last_read_end_bytes,
+ range_pages << PAGE_SHIFT,
+ range_pages << PAGE_SHIFT);
+}
+
+/**
+ * We have observed slow mmap read performances for some
+ * applications. The problem is if access pattern is neither
+ * sequential nor stride, but could be still adjacent in a
+ * small range and then seek a random position.
+ *
+ * So the pattern could be something like this:
+ *
+ * [1M data] [hole] [0.5M data] [hole] [0.7M data] [1M data]
+ *
+ *
+ * Every time an application reads mmap data, it may not only
+ * read a single 4KB page, but aslo a cluster of nearby pages in
+ * a range(e.g. 1MB) of the first page after a cache miss.
+ *
+ * The readahead engine is modified to track the range size of
+ * a cluster of mmap reads, so that after a seek and/or cache miss,
+ * the range size is used to efficiently prefetch multiple pages
+ * in a single RPC rather than many small RPCs.
+ */
+static void ras_detect_cluster_range(struct ll_readahead_state *ras,
+ struct ll_sb_info *sbi,
+ unsigned long pos, unsigned long count)
+{
+ pgoff_t last_pages, pages;
+ pgoff_t end_idx = (pos + count - 1) >> PAGE_SHIFT;
+
+ last_pages = ras->ras_range_max_end_idx -
+ ras->ras_range_min_start_idx + 1;
+ /* First time come here */
+ if (!ras->ras_range_max_end_idx)
+ goto out;
+
+ /* Random or Stride read */
+ if (!is_loose_mmap_read(sbi, ras, pos))
+ goto out;
+
+ ras->ras_range_requests++;
+ if (ras->ras_range_max_end_idx < end_idx)
+ ras->ras_range_max_end_idx = end_idx;
+
+ if (ras->ras_range_min_start_idx > (pos >> PAGE_SHIFT))
+ ras->ras_range_min_start_idx = pos >> PAGE_SHIFT;
+
+ /* Out of range, consider it as random or stride */
+ pages = ras->ras_range_max_end_idx -
+ ras->ras_range_min_start_idx + 1;
+ if (pages <= sbi->ll_ra_info.ra_range_pages)
+ return;
+out:
+ ras->ras_last_range_pages = last_pages;
+ ras->ras_range_requests = 0;
+ ras->ras_range_min_start_idx = pos >> PAGE_SHIFT;
+ ras->ras_range_max_end_idx = end_idx;
}
static void ras_detect_read_pattern(struct ll_readahead_state *ras,
struct ll_sb_info *sbi,
- unsigned long pos, unsigned long count,
- bool mmap)
+ loff_t pos, size_t count, bool mmap)
{
bool stride_detect = false;
- unsigned long index = pos >> PAGE_SHIFT;
+ pgoff_t index = pos >> PAGE_SHIFT;
/*
* Reset the read-ahead window in two cases. First when the app seeks
*/
if (!read_in_stride_window(ras, pos, count)) {
ras_stride_reset(ras);
- ras->ras_window_len = 0;
- ras->ras_next_readahead = index;
+ ras->ras_window_pages = 0;
+ ras->ras_next_readahead_idx = index;
}
}
ras->ras_consecutive_bytes += count;
if (mmap) {
- unsigned int idx = (ras->ras_consecutive_bytes >> PAGE_SHIFT);
+ pgoff_t idx = ras->ras_consecutive_bytes >> PAGE_SHIFT;
+ unsigned long ra_range_pages =
+ max_t(unsigned long, RA_MIN_MMAP_RANGE_PAGES,
+ sbi->ll_ra_info.ra_range_pages);
- if ((idx >= 4 && idx % 4 == 0) || stride_detect)
+ if ((idx >= ra_range_pages &&
+ idx % ra_range_pages == 0) || stride_detect)
ras->ras_need_increase_window = true;
} else if ((ras->ras_consecutive_requests > 1 || stride_detect)) {
ras->ras_need_increase_window = true;
}
- ras->ras_last_read_end = pos + count - 1;
+ ras->ras_last_read_end_bytes = pos + count - 1;
}
-void ll_ras_enter(struct file *f, unsigned long pos, unsigned long count)
+void ll_ras_enter(struct file *f, loff_t pos, size_t count)
{
- struct ll_file_data *fd = LUSTRE_FPRIVATE(f);
+ struct ll_file_data *fd = f->private_data;
struct ll_readahead_state *ras = &fd->fd_ras;
struct inode *inode = file_inode(f);
unsigned long index = pos >> PAGE_SHIFT;
ras->ras_no_miss_check = false;
/*
* On the second access to a file smaller than the tunable
- * ra_max_read_ahead_whole_pages trigger RA on all pages in the
- * file up to ra_max_pages_per_file. This is simply a best effort
+ * ra_max_read_ahead_whole_pages trigger RA on all pages in the
+ * file up to ra_max_pages_per_file. This is simply a best effort
* and only occurs once per open file. Normal RA behavior is reverted
* to for subsequent IO.
*/
PAGE_SHIFT;
CDEBUG(D_READA, "kmsp %llu mwp %lu mp %lu\n", kms_pages,
- ra->ra_max_read_ahead_whole_pages, ra->ra_max_pages_per_file);
-
- if (kms_pages &&
- kms_pages <= ra->ra_max_read_ahead_whole_pages) {
- ras->ras_window_start = 0;
- ras->ras_next_readahead = index + 1;
- ras->ras_window_len = min(ra->ra_max_pages_per_file,
- ra->ra_max_read_ahead_whole_pages);
+ ra->ra_max_read_ahead_whole_pages,
+ ra->ra_max_pages_per_file);
+
+ if (kms_pages &&
+ kms_pages <= ra->ra_max_read_ahead_whole_pages) {
+ ras->ras_window_start_idx = 0;
+ ras->ras_next_readahead_idx = index + 1;
+ ras->ras_window_pages = min(ra->ra_max_pages_per_file,
+ ra->ra_max_read_ahead_whole_pages);
ras->ras_no_miss_check = true;
- GOTO(out_unlock, 0);
- }
- }
+ GOTO(out_unlock, 0);
+ }
+ }
ras_detect_read_pattern(ras, sbi, pos, count, false);
out_unlock:
spin_unlock(&ras->ras_lock);
}
static bool index_in_stride_window(struct ll_readahead_state *ras,
- unsigned int index)
+ pgoff_t index)
{
- unsigned long pos = index << PAGE_SHIFT;
- unsigned long offset;
+ loff_t pos = (loff_t)index << PAGE_SHIFT;
if (ras->ras_stride_length == 0 || ras->ras_stride_bytes == 0 ||
ras->ras_stride_bytes == ras->ras_stride_length)
return false;
if (pos >= ras->ras_stride_offset) {
- offset = (pos - ras->ras_stride_offset) %
- ras->ras_stride_length;
+ u64 offset;
+
+ div64_u64_rem(pos - ras->ras_stride_offset,
+ ras->ras_stride_length, &offset);
if (offset < ras->ras_stride_bytes ||
ras->ras_stride_length - offset < PAGE_SIZE)
return true;
}
/*
- * ll_ras_enter() is used to detect read pattern according to
- * pos and count.
+ * ll_ras_enter() is used to detect read pattern according to pos and count.
*
* ras_update() is used to detect cache miss and
* reset window or increase window accordingly
*/
static void ras_update(struct ll_sb_info *sbi, struct inode *inode,
- struct ll_readahead_state *ras, unsigned long index,
- enum ras_update_flags flags)
+ struct ll_readahead_state *ras, pgoff_t index,
+ enum ras_update_flags flags, struct cl_io *io)
{
struct ll_ra_info *ra = &sbi->ll_ra_info;
bool hit = flags & LL_RAS_HIT;
if (ras->ras_no_miss_check)
GOTO(out_unlock, 0);
- if (flags & LL_RAS_MMAP)
- ras_detect_read_pattern(ras, sbi, index << PAGE_SHIFT,
+ if (io && io->ci_rand_read)
+ GOTO(out_unlock, 0);
+
+ if (io && io->ci_seq_read) {
+ if (!hit) {
+ /* to avoid many small read RPC here */
+ ras->ras_window_pages = sbi->ll_ra_info.ra_range_pages;
+ ll_ra_stats_inc_sbi(sbi, RA_STAT_MMAP_RANGE_READ);
+ }
+ goto skip;
+ }
+
+ if (flags & LL_RAS_MMAP) {
+ unsigned long ra_pages;
+
+ ras_detect_cluster_range(ras, sbi, index << PAGE_SHIFT,
+ PAGE_SIZE);
+ ras_detect_read_pattern(ras, sbi, (loff_t)index << PAGE_SHIFT,
PAGE_SIZE, true);
- if (!hit && ras->ras_window_len &&
- index < ras->ras_next_readahead &&
- pos_in_window(index, ras->ras_window_start, 0,
- ras->ras_window_len)) {
+ /* we did not detect anything but we could prefetch */
+ if (!ras->ras_need_increase_window &&
+ ras->ras_window_pages <= sbi->ll_ra_info.ra_range_pages &&
+ ras->ras_range_requests >= 2) {
+ if (!hit) {
+ ra_pages = max_t(unsigned long,
+ RA_MIN_MMAP_RANGE_PAGES,
+ ras->ras_last_range_pages);
+ if (index < ra_pages / 2)
+ index = 0;
+ else
+ index -= ra_pages / 2;
+ ras->ras_window_pages = ra_pages;
+ ll_ra_stats_inc_sbi(sbi,
+ RA_STAT_MMAP_RANGE_READ);
+ } else {
+ ras->ras_window_pages = 0;
+ }
+ goto skip;
+ }
+ }
+
+ if (!hit && ras->ras_window_pages &&
+ index < ras->ras_next_readahead_idx &&
+ pos_in_window(index, ras->ras_window_start_idx, 0,
+ ras->ras_window_pages)) {
ll_ra_stats_inc_sbi(sbi, RA_STAT_MISS_IN_WINDOW);
ras->ras_need_increase_window = false;
* is still intersect with normal sequential
* read-ahead window.
*/
- if (ras->ras_window_start <
- ras->ras_stride_offset)
+ if (ras->ras_window_start_idx < ras->ras_stride_offset)
ras_stride_reset(ras);
RAS_CDEBUG(ras);
} else {
GOTO(out_unlock, 0);
}
}
+
+skip:
ras_set_start(ras, index);
if (stride_io_mode(ras)) {
/* Since stride readahead is sentivite to the offset
* of read-ahead, so we use original offset here,
- * instead of ras_window_start, which is RPC aligned */
- ras->ras_next_readahead = max(index + 1,
- ras->ras_next_readahead);
- ras->ras_window_start =
- max(ras->ras_stride_offset >> PAGE_SHIFT,
- ras->ras_window_start);
+ * instead of ras_window_start_idx, which is RPC aligned.
+ */
+ ras->ras_next_readahead_idx = max(index + 1,
+ ras->ras_next_readahead_idx);
+ ras->ras_window_start_idx =
+ max_t(pgoff_t, ras->ras_window_start_idx,
+ ras->ras_stride_offset >> PAGE_SHIFT);
} else {
- if (ras->ras_next_readahead < ras->ras_window_start)
- ras->ras_next_readahead = ras->ras_window_start;
+ if (ras->ras_next_readahead_idx < ras->ras_window_start_idx)
+ ras->ras_next_readahead_idx = ras->ras_window_start_idx;
if (!hit)
- ras->ras_next_readahead = index + 1;
+ ras->ras_next_readahead_idx = index + 1;
}
if (ras->ras_need_increase_window) {
ENTRY;
if (wbc->range_cyclic) {
- start = mapping->writeback_index << PAGE_SHIFT;
+ start = (loff_t)mapping->writeback_index << PAGE_SHIFT;
end = OBD_OBJECT_EOF;
} else {
start = wbc->range_start;
struct ll_cl_context *ll_cl_find(struct file *file)
{
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct ll_file_data *fd = file->private_data;
struct ll_cl_context *lcc;
struct ll_cl_context *found = NULL;
void ll_cl_add(struct file *file, const struct lu_env *env, struct cl_io *io,
enum lcc_type type)
{
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct ll_file_data *fd = file->private_data;
struct ll_cl_context *lcc = &ll_env_info(env)->lti_io_ctx;
memset(lcc, 0, sizeof(*lcc));
void ll_cl_remove(struct file *file, const struct lu_env *env)
{
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct ll_file_data *fd = file->private_data;
struct ll_cl_context *lcc = &ll_env_info(env)->lti_io_ctx;
write_lock(&fd->fd_lock);
{
struct inode *inode = vvp_object_inode(page->cp_obj);
struct ll_sb_info *sbi = ll_i2sbi(inode);
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
- struct ll_readahead_state *ras = &fd->fd_ras;
+ struct ll_file_data *fd = NULL;
+ struct ll_readahead_state *ras = NULL;
struct cl_2queue *queue = &io->ci_queue;
struct cl_sync_io *anchor = NULL;
struct vvp_page *vpg;
- int rc = 0;
+ int rc = 0, rc2 = 0;
bool uptodate;
+ pgoff_t io_start_index;
+ pgoff_t io_end_index;
ENTRY;
+ if (file) {
+ fd = file->private_data;
+ ras = &fd->fd_ras;
+ }
+
vpg = cl2vvp_page(cl_object_page_slice(page->cp_obj, page));
uptodate = vpg->vpg_defer_uptodate;
- if (sbi->ll_ra_info.ra_max_pages_per_file > 0 &&
- sbi->ll_ra_info.ra_max_pages > 0 &&
- !vpg->vpg_ra_updated) {
+ if (ll_readahead_enabled(sbi) && !vpg->vpg_ra_updated && ras) {
struct vvp_io *vio = vvp_env_io(env);
enum ras_update_flags flags = 0;
flags |= LL_RAS_HIT;
if (!vio->vui_ra_valid)
flags |= LL_RAS_MMAP;
- ras_update(sbi, inode, ras, vvp_index(vpg), flags);
+ ras_update(sbi, inode, ras, vvp_index(vpg), flags, io);
}
cl_2queue_init(queue);
cl_2queue_add(queue, page);
}
- if (sbi->ll_ra_info.ra_max_pages_per_file > 0 &&
- sbi->ll_ra_info.ra_max_pages > 0) {
- int rc2;
+ io_start_index = cl_index(io->ci_obj, io->u.ci_rw.crw_pos);
+ io_end_index = cl_index(io->ci_obj, io->u.ci_rw.crw_pos +
+ io->u.ci_rw.crw_count - 1);
+ if (ll_readahead_enabled(sbi) && ras && !io->ci_rand_read) {
+ pgoff_t skip_index = 0;
+ if (ras->ras_next_readahead_idx < vvp_index(vpg))
+ skip_index = vvp_index(vpg);
rc2 = ll_readahead(env, io, &queue->c2_qin, ras,
- uptodate, file);
- CDEBUG(D_READA, DFID "%d pages read ahead at %lu\n",
+ uptodate, file, skip_index);
+ CDEBUG(D_READA, DFID " %d pages read ahead at %lu\n",
+ PFID(ll_inode2fid(inode)), rc2, vvp_index(vpg));
+ } else if (vvp_index(vpg) == io_start_index &&
+ io_end_index - io_start_index > 0) {
+ rc2 = ll_readpages(env, io, &queue->c2_qin, io_start_index + 1,
+ io_end_index);
+ CDEBUG(D_READA, DFID " %d pages read at %lu\n",
PFID(ll_inode2fid(inode)), rc2, vvp_index(vpg));
}
struct ll_readahead_work *lrw;
struct inode *inode = file_inode(file);
struct ll_sb_info *sbi = ll_i2sbi(inode);
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct ll_file_data *fd = file->private_data;
struct ll_readahead_state *ras = &fd->fd_ras;
struct ll_ra_info *ra = &sbi->ll_ra_info;
unsigned long throttle;
- unsigned long start = ras_align(ras, ras->ras_next_readahead, NULL);
- unsigned long end = start + pages - 1;
+ pgoff_t start_idx = ras_align(ras, ras->ras_next_readahead_idx);
+ pgoff_t end_idx = start_idx + pages - 1;
+
+ /**
+ * In case we have a limited max_cached_mb, readahead
+ * should be stopped if it have run out of all LRU slots.
+ */
+ if (atomic_read(&ra->ra_cur_pages) >= sbi->ll_cache->ccc_lru_max) {
+ ll_ra_stats_inc(inode, RA_STAT_MAX_IN_FLIGHT);
+ return 0;
+ }
throttle = min(ra->ra_async_pages_per_file_threshold,
ra->ra_max_pages_per_file);
* we do async readahead, allowing the user thread to do fast i/o.
*/
if (stride_io_mode(ras) || !throttle ||
- ras->ras_window_len < throttle)
+ ras->ras_window_pages < throttle ||
+ atomic_read(&ra->ra_async_inflight) > ra->ra_async_max_active)
return 0;
if ((atomic_read(&ra->ra_cur_pages) + pages) > ra->ra_max_pages)
return 0;
- if (ras->ras_async_last_readpage == start)
+ if (ras->ras_async_last_readpage_idx == start_idx)
return 1;
/* ll_readahead_work_free() free it */
OBD_ALLOC_PTR(lrw);
if (lrw) {
+ atomic_inc(&sbi->ll_ra_info.ra_async_inflight);
lrw->lrw_file = get_file(file);
- lrw->lrw_start = start;
- lrw->lrw_end = end;
+ lrw->lrw_start_idx = start_idx;
+ lrw->lrw_end_idx = end_idx;
spin_lock(&ras->ras_lock);
- ras->ras_next_readahead = end + 1;
- ras->ras_async_last_readpage = start;
+ ras->ras_next_readahead_idx = end_idx + 1;
+ ras->ras_async_last_readpage_idx = start_idx;
spin_unlock(&ras->ras_lock);
+ memcpy(lrw->lrw_jobid, ll_i2info(inode)->lli_jobid,
+ sizeof(lrw->lrw_jobid));
ll_readahead_work_add(inode, lrw);
} else {
return -ENOMEM;
return 2;
}
+/*
+ * Check if we can issue a readahead RPC, if that is
+ * the case, we can't do fast IO because we will need
+ * a cl_io to issue the RPC.
+ */
+static bool ll_use_fast_io(struct file *file,
+ struct ll_readahead_state *ras, pgoff_t index)
+{
+ unsigned long fast_read_pages =
+ max(RA_REMAIN_WINDOW_MIN, ras->ras_rpc_pages);
+ loff_t skip_pages;
+ loff_t stride_bytes = ras->ras_stride_bytes;
+
+ if (stride_io_mode(ras) && stride_bytes) {
+ skip_pages = (ras->ras_stride_length +
+ ras->ras_stride_bytes - 1) / stride_bytes;
+ skip_pages *= fast_read_pages;
+ } else {
+ skip_pages = fast_read_pages;
+ }
+
+ if (ras->ras_window_start_idx + ras->ras_window_pages <
+ ras->ras_next_readahead_idx + skip_pages ||
+ kickoff_async_readahead(file, fast_read_pages) > 0)
+ return true;
+
+ return false;
+}
+
int ll_readpage(struct file *file, struct page *vmpage)
{
struct inode *inode = file_inode(file);
if (io == NULL) { /* fast read */
struct inode *inode = file_inode(file);
- struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
+ struct ll_file_data *fd = file->private_data;
struct ll_readahead_state *ras = &fd->fd_ras;
struct lu_env *local_env = NULL;
- unsigned long fast_read_pages =
- max(RA_REMAIN_WINDOW_MIN, ras->ras_rpc_size);
struct vvp_page *vpg;
result = -ENODATA;
/* For fast read, it updates read ahead state only
* if the page is hit in cache because non cache page
* case will be handled by slow read later. */
- ras_update(sbi, inode, ras, vvp_index(vpg), flags);
+ ras_update(sbi, inode, ras, vvp_index(vpg), flags, io);
/* avoid duplicate ras_update() call */
vpg->vpg_ra_updated = 1;
- /* Check if we can issue a readahead RPC, if that is
- * the case, we can't do fast IO because we will need
- * a cl_io to issue the RPC. */
- if (ras->ras_window_start + ras->ras_window_len <
- ras->ras_next_readahead + fast_read_pages ||
- kickoff_async_readahead(file, fast_read_pages) > 0)
+ if (ll_use_fast_io(file, ras, vvp_index(vpg)))
result = 0;
}
RETURN(result);
}
+ /**
+ * Direct read can fall back to buffered read, but DIO is done
+ * with lockless i/o, and buffered requires LDLM locking, so in
+ * this case we must restart without lockless.
+ */
+ if (file->f_flags & O_DIRECT &&
+ lcc && lcc->lcc_type == LCC_RW &&
+ !io->ci_dio_lock) {
+ unlock_page(vmpage);
+ io->ci_dio_lock = 1;
+ io->ci_need_restart = 1;
+ RETURN(-ENOLCK);
+ }
+
LASSERT(io->ci_state == CIS_IO_GOING);
page = cl_page_find(env, clob, vmpage->index, vmpage, CPT_CACHEABLE);
if (!IS_ERR(page)) {
git://git.whamcloud.com / fs / lustre-release.git / blobdiff