* Copyright (C) 2009 The Regents of the University of California
* Written by Michael Vrable <mvrable@cs.ucsd.edu>
*
- * TODO: Licensing
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
*/
#define _GNU_SOURCE
* then we'll just skip the file on this pass. */
if (g_mutex_trylock(cachefile->lock)) {
int64_t age = bluesky_get_current_time() - cachefile->atime;
- g_print("%s addr=%p mapcount=%d refcount=%d size=%d atime_age=%f",
- cachefile->filename, cachefile->addr, cachefile->mapcount,
- cachefile->refcount, cachefile->disk_used, age / 1e6);
- if (cachefile->fetching)
- g_print(" (fetching)");
- g_print("\n");
+ if (bluesky_verbose) {
+ g_print("%s addr=%p mapcount=%d refcount=%d size=%d atime_age=%f",
+ cachefile->filename, cachefile->addr, cachefile->mapcount,
+ cachefile->refcount, cachefile->disk_used, age / 1e6);
+ if (cachefile->fetching)
+ g_print(" (fetching)");
+ g_print("\n");
+ }
gboolean deletion_candidate = FALSE;
if (g_atomic_int_get(&fs->log->disk_used)
}
if (deletion_candidate) {
- g_print(" ...deleting\n");
+ if (bluesky_verbose) {
+ g_print(" ...deleting\n");
+ }
if (unlinkat(fs->log->dirfd, cachefile->filename, 0) < 0) {
fprintf(stderr, "Unable to unlink journal %s: %m\n",
cachefile->filename);
g_atomic_int_add(&fs->log->disk_used, -cachefile->disk_used);
g_hash_table_remove(fs->log->mmap_cache, cachefile->filename);
bluesky_rangeset_free(cachefile->items);
+ if (cachefile->prefetches != NULL)
+ bluesky_rangeset_free(cachefile->prefetches);
g_mutex_unlock(cachefile->lock);
g_mutex_free(cachefile->lock);
g_cond_free(cachefile->cond);
g_thread_create((GThreadFunc)flushd_task, fs, FALSE, NULL);
}
+/* How urgent is flushing out data? Returns one of several values:
+ * 0 - memory state is fine
+ * 1 - should launch flushd if not already running
+ * 2 - should delay writers while memory frees up
+ * 3 - should block writers until memory frees up
+ */
+static int compute_pressure(BlueSkyFS *fs)
+{
+ /* LEVEL 3 */
+ /* Too much dirty data in memory? */
+ if (g_atomic_int_get(&fs->cache_dirty)
+ + g_atomic_int_get(&fs->cache_log_dirty)
+ > bluesky_watermark_high_dirty)
+ {
+ g_print("pressure: too much dirty data (3)\n");
+ return 3;
+ }
+
+ /* Too much uncommitted data in the journal on disk, not yet flushed to the
+ * cloud? */
+ /*printf("Dirty journals: %d to %d\n",
+ fs->log->journal_watermark, fs->log->seq_num);*/
+ int dirty_limit;
+ dirty_limit = bluesky_options.cache_size / (LOG_SEGMENT_SIZE / 1024) / 2;
+ int dirty_journals = fs->log->seq_num - fs->log->journal_watermark + 1;
+ if (dirty_journals > 1 && dirty_journals >= dirty_limit) {
+ printf("pressure: too many dirty journals (%d >= %d) (3)\n",
+ dirty_journals, dirty_limit);
+ return 3;
+ }
+
+ /* LEVEL 2 */
+ if (g_atomic_int_get(&fs->cache_dirty) > bluesky_watermark_med2_dirty) {
+ g_print("pressure: too much dirty data (2)\n");
+ return 2;
+ }
+
+ if (dirty_journals > 1 && dirty_journals > dirty_limit * 3 / 4) {
+ printf("pressure: many dirty journals (%d), should start writeback (2)\n",
+ dirty_journals);
+ return 2;
+ }
+
+ /* LEVEL 1 */
+ if (g_atomic_int_get(&fs->cache_dirty) > bluesky_watermark_medium_dirty) {
+ g_print("pressure: too much dirty data (1)\n");
+ return 1;
+ }
+
+ if (dirty_journals > 1 && dirty_journals > dirty_limit / 2) {
+ printf("pressure: many dirty journals (%d), should start writeback (1)\n",
+ dirty_journals);
+ return 1;
+ }
+
+ return 0;
+}
+
void bluesky_flushd_invoke_conditional(BlueSkyFS *fs)
{
- if (g_atomic_int_get(&fs->cache_dirty) < bluesky_watermark_medium_dirty)
+ int pressure = compute_pressure(fs);
+ if (pressure == 0)
return;
if (bluesky_verbose) {
/* If the system is under heavy memory pressure, actually delay execution
* so the flush daemon can catch up. */
- while (g_atomic_int_get(&fs->cache_dirty)
- + g_atomic_int_get(&fs->cache_log_dirty)
- > bluesky_watermark_high_dirty) {
+ while (pressure > 1) {
g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG,
"Waiting due to memory pressure, dirty=%d + %d",
g_atomic_int_get(&fs->cache_dirty),
g_atomic_int_get(&fs->cache_log_dirty));
g_mutex_lock(fs->lock);
- g_cond_wait(fs->flushd_cond, fs->lock);
+ pressure = compute_pressure(fs);
+ if (pressure > 2) {
+ g_cond_wait(fs->flushd_cond, fs->lock);
+ } else if (pressure > 1) {
+ /* Wait for up to 10 seconds. */
+ GTimeVal timeout;
+ g_get_current_time(&timeout);
+ g_time_val_add(&timeout, 10 * 1000 * 1000);
+ g_cond_timed_wait(fs->flushd_cond, fs->lock, &timeout);
+ }
g_mutex_unlock(fs->lock);
+ pressure = compute_pressure(fs);
+ if (pressure == 1)
+ break; /* Do not loop indefinitely for a pressure of 1 */
}
}
projects / bluesky.git / blobdiff