}
LUSTRE_RW_ATTR(tiny_write);
+static ssize_t max_read_ahead_async_active_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
+ ll_kset.kobj);
+
+ return snprintf(buf, PAGE_SIZE, "%u\n",
+ sbi->ll_ra_info.ra_async_max_active);
+}
+
+static ssize_t max_read_ahead_async_active_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buffer,
+ size_t count)
+{
+ unsigned int val;
+ int rc;
+ struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
+ ll_kset.kobj);
+
+ rc = kstrtouint(buffer, 10, &val);
+ if (rc)
+ return rc;
+
+ if (val < 1 || val > WQ_UNBOUND_MAX_ACTIVE) {
+ CERROR("%s: cannot set max_read_ahead_async_active=%u %s than %u\n",
+ sbi->ll_fsname, val,
+ val < 1 ? "smaller" : "larger",
+ val < 1 ? 1 : WQ_UNBOUND_MAX_ACTIVE);
+ return -ERANGE;
+ }
+
+ sbi->ll_ra_info.ra_async_max_active = val;
+ workqueue_set_max_active(sbi->ll_ra_info.ll_readahead_wq, val);
+
+ return count;
+}
+LUSTRE_RW_ATTR(max_read_ahead_async_active);
+
+static ssize_t read_ahead_async_file_threshold_mb_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
+ ll_kset.kobj);
+
+ return snprintf(buf, PAGE_SIZE, "%lu\n",
+ PAGES_TO_MiB(sbi->ll_ra_info.ra_async_pages_per_file_threshold));
+}
+
+static ssize_t
+read_ahead_async_file_threshold_mb_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buffer, size_t count)
+{
+ unsigned long pages_number;
+ unsigned long max_ra_per_file;
+ struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
+ ll_kset.kobj);
+ int rc;
+
+ rc = kstrtoul(buffer, 10, &pages_number);
+ if (rc)
+ return rc;
+
+ pages_number = MiB_TO_PAGES(pages_number);
+ max_ra_per_file = sbi->ll_ra_info.ra_max_pages_per_file;
+ if (pages_number < 0 || pages_number > max_ra_per_file) {
+ CERROR("%s: can't set read_ahead_async_file_threshold_mb=%lu > "
+ "max_read_readahead_per_file_mb=%lu\n", sbi->ll_fsname,
+ PAGES_TO_MiB(pages_number),
+ PAGES_TO_MiB(max_ra_per_file));
+ return -ERANGE;
+ }
+ sbi->ll_ra_info.ra_async_pages_per_file_threshold = pages_number;
+
+ return count;
+}
+LUSTRE_RW_ATTR(read_ahead_async_file_threshold_mb);
+
static ssize_t fast_read_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
&lustre_attr_file_heat.attr,
&lustre_attr_heat_decay_percentage.attr,
&lustre_attr_heat_period_second.attr,
+ &lustre_attr_max_read_ahead_async_active.attr,
+ &lustre_attr_read_ahead_async_file_threshold_mb.attr,
NULL,
};
[RA_STAT_EOF] = "read-ahead to EOF",
[RA_STAT_MAX_IN_FLIGHT] = "hit max r-a issue",
[RA_STAT_WRONG_GRAB_PAGE] = "wrong page from grab_cache_page",
- [RA_STAT_FAILED_REACH_END] = "failed to reach end"
+ [RA_STAT_FAILED_REACH_END] = "failed to reach end",
+ [RA_STAT_ASYNC] = "async readahead",
+ [RA_STAT_FAILED_FAST_READ] = "failed to fast read",
};
int ll_debugfs_register_super(struct super_block *sb, const char *name)
#include <asm/uaccess.h>
#include <linux/fs.h>
+#include <linux/file.h>
#include <linux/stat.h>
#include <asm/uaccess.h>
#include <linux/mm.h>
#define RAS_CDEBUG(ras) \
CDEBUG(D_READA, \
"lrp %lu cr %lu cp %lu ws %lu wl %lu nra %lu rpc %lu " \
- "r %lu ri %lu csr %lu sf %lu sp %lu sl %lu\n", \
+ "r %lu ri %lu csr %lu sf %lu sp %lu sl %lu lr %lu\n", \
ras->ras_last_readpage, ras->ras_consecutive_requests, \
ras->ras_consecutive_pages, ras->ras_window_start, \
ras->ras_window_len, ras->ras_next_readahead, \
ras->ras_rpc_size, \
ras->ras_requests, ras->ras_request_index, \
ras->ras_consecutive_stride_requests, ras->ras_stride_offset, \
- ras->ras_stride_pages, ras->ras_stride_length)
+ ras->ras_stride_pages, ras->ras_stride_length, \
+ ras->ras_async_last_readpage)
static int index_in_window(unsigned long index, unsigned long point,
unsigned long before, unsigned long after)
return count;
}
+static void ll_readahead_work_free(struct ll_readahead_work *work)
+{
+ fput(work->lrw_file);
+ OBD_FREE_PTR(work);
+}
+
+static void ll_readahead_handle_work(struct work_struct *wq);
+static void ll_readahead_work_add(struct inode *inode,
+ struct ll_readahead_work *work)
+{
+ INIT_WORK(&work->lrw_readahead_work, ll_readahead_handle_work);
+ queue_work(ll_i2sbi(inode)->ll_ra_info.ll_readahead_wq,
+ &work->lrw_readahead_work);
+}
+
+static int ll_readahead_file_kms(const struct lu_env *env,
+ struct cl_io *io, __u64 *kms)
+{
+ struct cl_object *clob;
+ struct inode *inode;
+ struct cl_attr *attr = vvp_env_thread_attr(env);
+ int ret;
+
+ clob = io->ci_obj;
+ inode = vvp_object_inode(clob);
+
+ cl_object_attr_lock(clob);
+ ret = cl_object_attr_get(env, clob, attr);
+ cl_object_attr_unlock(clob);
+
+ if (ret != 0)
+ RETURN(ret);
+
+ *kms = attr->cat_kms;
+ return 0;
+}
+
+static void ll_readahead_handle_work(struct work_struct *wq)
+{
+ struct ll_readahead_work *work;
+ struct lu_env *env;
+ __u16 refcheck;
+ struct ra_io_arg *ria;
+ struct inode *inode;
+ struct ll_file_data *fd;
+ struct ll_readahead_state *ras;
+ struct cl_io *io;
+ struct cl_2queue *queue;
+ pgoff_t ra_end = 0;
+ unsigned long len, mlen = 0;
+ struct file *file;
+ __u64 kms;
+ int rc;
+ unsigned long end_index;
+
+ work = container_of(wq, struct ll_readahead_work,
+ lrw_readahead_work);
+ fd = LUSTRE_FPRIVATE(work->lrw_file);
+ ras = &fd->fd_ras;
+ file = work->lrw_file;
+ inode = file_inode(file);
+
+ env = cl_env_alloc(&refcheck, LCT_NOREF);
+ if (IS_ERR(env))
+ GOTO(out_free_work, rc = PTR_ERR(env));
+
+ io = vvp_env_thread_io(env);
+ ll_io_init(io, file, CIT_READ);
+
+ rc = ll_readahead_file_kms(env, io, &kms);
+ if (rc != 0)
+ GOTO(out_put_env, rc);
+
+ if (kms == 0) {
+ ll_ra_stats_inc(inode, RA_STAT_ZERO_LEN);
+ GOTO(out_put_env, rc = 0);
+ }
+
+ ria = &ll_env_info(env)->lti_ria;
+ memset(ria, 0, sizeof(*ria));
+
+ ria->ria_start = work->lrw_start;
+ /* 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;
+ ria->ria_eof = true;
+ }
+ if (work->lrw_end <= work->lrw_start)
+ 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);
+
+ CDEBUG(D_READA,
+ "async reserved pages: %lu/%lu/%lu, ra_cur %d, ra_max %lu\n",
+ ria->ria_reserved, len, mlen,
+ 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) {
+ 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);
+ GOTO(out_put_env, rc = 0);
+ }
+ }
+
+ rc = cl_io_rw_init(env, io, CIT_READ, ria->ria_start, len);
+ if (rc)
+ GOTO(out_put_env, rc);
+
+ vvp_env_io(env)->vui_io_subtype = IO_NORMAL;
+ vvp_env_io(env)->vui_fd = fd;
+ io->ci_state = CIS_LOCKED;
+ io->ci_async_readahead = true;
+ rc = cl_io_start(env, io);
+ if (rc)
+ GOTO(out_io_fini, rc);
+
+ queue = &io->ci_queue;
+ cl_2queue_init(queue);
+
+ rc = ll_read_ahead_pages(env, io, &queue->c2_qin, ras, ria, &ra_end);
+ if (ria->ria_reserved != 0)
+ ll_ra_count_put(ll_i2sbi(inode), ria->ria_reserved);
+ if (queue->c2_qin.pl_nr > 0) {
+ int count = queue->c2_qin.pl_nr;
+
+ rc = cl_io_submit_rw(env, io, CRT_READ, queue);
+ if (rc == 0)
+ task_io_account_read(PAGE_SIZE * count);
+ }
+ if (ria->ria_end == ra_end && ra_end == (kms >> PAGE_SHIFT))
+ ll_ra_stats_inc(inode, RA_STAT_EOF);
+
+ if (ra_end != ria->ria_end)
+ ll_ra_stats_inc(inode, RA_STAT_FAILED_REACH_END);
+
+ /* TODO: discard all pages until page reinit route is implemented */
+ cl_page_list_discard(env, io, &queue->c2_qin);
+
+ /* Unlock unsent read pages in case of error. */
+ cl_page_list_disown(env, io, &queue->c2_qin);
+
+ cl_2queue_fini(env, queue);
+out_io_fini:
+ cl_io_end(env, io);
+ cl_io_fini(env, io);
+out_put_env:
+ cl_env_put(env, &refcheck);
+out_free_work:
+ if (ra_end > 0)
+ ll_ra_stats_inc_sbi(ll_i2sbi(inode), RA_STAT_ASYNC);
+ 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 ll_readahead_state *ras, bool hit,
+ struct file *file)
{
struct vvp_io *vio = vvp_env_io(env);
struct ll_thread_info *lti = ll_env_info(env);
- struct cl_attr *attr = vvp_env_thread_attr(env);
unsigned long len, mlen = 0;
pgoff_t ra_end = 0, start = 0, end = 0;
struct inode *inode;
inode = vvp_object_inode(clob);
memset(ria, 0, sizeof *ria);
-
- cl_object_attr_lock(clob);
- ret = cl_object_attr_get(env, clob, attr);
- cl_object_attr_unlock(clob);
-
+ ret = ll_readahead_file_kms(env, io, &kms);
if (ret != 0)
RETURN(ret);
- kms = attr->cat_kms;
+
if (kms == 0) {
ll_ra_stats_inc(inode, RA_STAT_ZERO_LEN);
RETURN(0);
int rc2;
rc2 = ll_readahead(env, io, &queue->c2_qin, ras,
- uptodate);
+ uptodate, file);
CDEBUG(D_READA, DFID "%d pages read ahead at %lu\n",
PFID(ll_inode2fid(inode)), rc2, vvp_index(vpg));
}
RETURN(rc);
}
+/*
+ * Possible return value:
+ * 0 no async readahead triggered and fast read could not be used.
+ * 1 no async readahead, but fast read could be used.
+ * 2 async readahead triggered and fast read could be used too.
+ * < 0 on error.
+ */
+static int kickoff_async_readahead(struct file *file, unsigned long pages)
+{
+ 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_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;
+
+ throttle = min(ra->ra_async_pages_per_file_threshold,
+ ra->ra_max_pages_per_file);
+ /*
+ * If this is strided i/o or the window is smaller than the
+ * throttle limit, we do not do async readahead. Otherwise,
+ * we do async readahead, allowing the user thread to do fast i/o.
+ */
+ if (stride_io_mode(ras) || !throttle ||
+ ras->ras_window_len < throttle)
+ return 0;
+
+ if ((atomic_read(&ra->ra_cur_pages) + pages) > ra->ra_max_pages)
+ return 0;
+
+ if (ras->ras_async_last_readpage == start)
+ return 1;
+
+ /* ll_readahead_work_free() free it */
+ OBD_ALLOC_PTR(lrw);
+ if (lrw) {
+ lrw->lrw_file = get_file(file);
+ lrw->lrw_start = start;
+ lrw->lrw_end = end;
+ spin_lock(&ras->ras_lock);
+ ras->ras_next_readahead = end + 1;
+ ras->ras_async_last_readpage = start;
+ spin_unlock(&ras->ras_lock);
+ ll_readahead_work_add(inode, lrw);
+ } else {
+ return -ENOMEM;
+ }
+
+ return 2;
+}
+
int ll_readpage(struct file *file, struct page *vmpage)
{
struct inode *inode = file_inode(file);
const struct lu_env *env = NULL;
struct cl_io *io = NULL;
struct cl_page *page;
+ struct ll_sb_info *sbi = ll_i2sbi(inode);
int result;
ENTRY;
page = cl_vmpage_page(vmpage, clob);
if (page == NULL) {
unlock_page(vmpage);
+ ll_ra_stats_inc_sbi(sbi, RA_STAT_FAILED_FAST_READ);
RETURN(result);
}
- if (!env) {
- local_env = cl_env_percpu_get();
- env = local_env;
- }
-
vpg = cl2vvp_page(cl_object_page_slice(page->cp_obj, page));
if (vpg->vpg_defer_uptodate) {
enum ras_update_flags flags = LL_RAS_HIT;
/* 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(ll_i2sbi(inode), inode, ras, vvp_index(vpg),
- flags);
+ ras_update(sbi, inode, ras, vvp_index(vpg), flags);
/* avoid duplicate ras_update() call */
vpg->vpg_ra_updated = 1;
* 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) {
- /* export the page and skip io stack */
- vpg->vpg_ra_used = 1;
- cl_page_export(env, page, 1);
+ ras->ras_next_readahead + fast_read_pages ||
+ kickoff_async_readahead(file, fast_read_pages) > 0)
result = 0;
- }
}
+ if (!env) {
+ local_env = cl_env_percpu_get();
+ env = local_env;
+ }
+
+ /* export the page and skip io stack */
+ if (result == 0) {
+ vpg->vpg_ra_used = 1;
+ cl_page_export(env, page, 1);
+ } else {
+ ll_ra_stats_inc_sbi(sbi, RA_STAT_FAILED_FAST_READ);
+ }
/* release page refcount before unlocking the page to ensure
* the object won't be destroyed in the calling path of
* cl_page_put(). Please see comment in ll_releasepage(). */
git://git.whamcloud.com / fs / lustre-release.git / commitdiff