EX-8568 lipe: lpcc_purge can disable force scanning

when force_scan_interval is set to -1, lpcc_purge will never
start force scanning.

Signed-off-by: Lei Feng <flei@whamcloud.com>
Test-Parameters: trivial
Change-Id: I21bcadb97f09622eae08af73082196e816b2c9ae
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/53032
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lipe/man/lpcc.conf.5 b/lipe/man/lpcc.conf.5
index 1e1a976..7aace93 100644 (file)
--- a/lipe/man/lpcc.conf.5
+++ b/lipe/man/lpcc.conf.5
@@ -45,7 +45,8 @@ seconds by default.
 .BR purge.force_scan_interval
 The interval for lpcc_purge to scan cache device forcefully even if its usage
 is not higher than \fBpurge.high_usage\fR to refresh some statistics data.
-It is 1800 seconds by default.
+It is 1800 seconds by default. This function can be disabled by setting the
+value to -1.
 .TP
 .BR purge.scan_threads
 How many threads are used to scan cache device in parallel. It is 1 thread by

diff --git a/lipe/src/lpcc_purge.c b/lipe/src/lpcc_purge.c
index 00a38b7..a80f249 100644 (file)
--- a/lipe/src/lpcc_purge.c
+++ b/lipe/src/lpcc_purge.c
@@ -38,6 +38,7 @@
 #define DEF_FORCE_SCAN_INTERVAL                (30 * 60)
 #define MIN_FORCE_SCAN_INTERVAL                (60)
 #define MAX_FORCE_SCAN_INTERVAL                (24 * 60 * 60)
+#define DISABLED_FORCE_SCAN_INTERVAL   (-1)
 
 #define OPT_DRY_RUN                    1
 #define OPT_CANDIDATE_NUM              2
@@ -417,7 +418,7 @@ static void usage(void)
                "\t-t, --scan-threads=NUM, scanning threads (default: %u)\n"
                "\t    --candidate-num=NUM, candidate number of approximate LRU (default: %d, min: %d, max: %d)\n"
                "\t    --max-scan-secs=NUM, max seconds to scan continously before purging (default: %d, min: %d, max: %d)\n"
-               "\t    --force-scan-interval=NUM, seconds to next forceful scanning (default: %d, min: %d, max: %d)\n"
+               "\t    --force-scan-interval=NUM, seconds to next forceful scanning (default: %d, min: %d, max: %d, disabled: %d)\n"
                "\t-w, --dump=FILE, dump stats to FILE when signal USR1 is recieved (default: /var/run/lpcc_purge-RWID.stats)\n"
                "\t    --pidfile=FILE, the pidfile name (default: /var/run/lpcc_purge-RWID.pid)\n"
                "\t    --clear-hashdir, clear empty hash dir after detaching file\n"
@@ -433,7 +434,7 @@ static void usage(void)
                DEF_CANDIDATE_NUM, MIN_CANDIDATE_NUM, MAX_CANDIDATE_NUM,
                DEF_MAX_SCAN_SECS, MIN_MAX_SCAN_SECS, MAX_MAX_SCAN_SECS,
                DEF_FORCE_SCAN_INTERVAL, MIN_FORCE_SCAN_INTERVAL,
-               MAX_FORCE_SCAN_INTERVAL
+               MAX_FORCE_SCAN_INTERVAL, DISABLED_FORCE_SCAN_INTERVAL
        );
 }
 
@@ -721,8 +722,9 @@ static void lpcc_purge_process_opt(int c, char *optarg)
                break;
        case OPT_FORCE_SCAN_INTERVAL:
                value = strtol(optarg, &endptr, 10);
-               if (*endptr != '\0' || value < MIN_FORCE_SCAN_INTERVAL ||
-                   value > MAX_FORCE_SCAN_INTERVAL) {
+               if (*endptr != '\0' || (value != DISABLED_FORCE_SCAN_INTERVAL &&
+                   (value < MIN_FORCE_SCAN_INTERVAL ||
+                    value > MAX_FORCE_SCAN_INTERVAL))) {
                        llapi_error(LLAPI_MSG_FATAL, -EINVAL,
                                    "invalid force-scan-interval: '%s'\n",
                                    optarg);
@@ -897,8 +899,9 @@ static void lpcc_purge_wait_for_scan(void)
                double usage = lpcc_purge_get_fs_usage(opt.o_cache);
                LPCC_PURGE_LOG(LLAPI_MSG_DEBUG, "usage: %.1f\n", usage);
                if (usage >= opt.o_high_usage || opt.o_dry_run ||
+                   (opt.o_force_scan_interval != DISABLED_FORCE_SCAN_INTERVAL &&
                    (now - xstats[1].xs_last_scan_time) >
-                    opt.o_force_scan_interval) {
+                    opt.o_force_scan_interval)) {
                        stats.s_start_usage = usage;
                        xstats[1].xs_last_scan_time = now;
                        break;