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Diffstat (limited to 'src/pmdas/gfs2/control.c')
| -rw-r--r-- | src/pmdas/gfs2/control.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/pmdas/gfs2/control.c b/src/pmdas/gfs2/control.c new file mode 100644 index 0000000..20d5c6f --- /dev/null +++ b/src/pmdas/gfs2/control.c @@ -0,0 +1,123 @@ +/* + * GFS2 trace-point metrics control. + * + * Copyright (c) 2013 - 2014 Red Hat. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "pmapi.h" +#include "impl.h" +#include "pmda.h" +#include "control.h" +#include "ftrace.h" +#include "worst_glock.h" +#include "latency.h" + +/* Locations of the enable files for the gfs2 tracepoints */ +const char *control_locations[] = { + [CONTROL_ALL] = "/sys/kernel/debug/tracing/events/gfs2/enable", + [CONTROL_GLOCK_STATE_CHANGE] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_glock_state_change/enable", + [CONTROL_GLOCK_PUT] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_glock_put/enable", + [CONTROL_DEMOTE_RQ] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_demote_rq/enable", + [CONTROL_PROMOTE] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_promote/enable", + [CONTROL_GLOCK_QUEUE] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_glock_queue/enable", + [CONTROL_GLOCK_LOCK_TIME] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_glock_lock_time/enable", + [CONTROL_PIN] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_pin/enable", + [CONTROL_LOG_FLUSH] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_log_flush/enable", + [CONTROL_LOG_BLOCKS] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_log_blocks/enable", + [CONTROL_AIL_FLUSH] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_ail_flush/enable", + [CONTROL_BLOCK_ALLOC] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_block_alloc/enable", + [CONTROL_BMAP] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_bmap/enable", + [CONTROL_RS] = "/sys/kernel/debug/tracing/events/gfs2/gfs2_rs/enable", + [CONTROL_BUFFER_SIZE_KB] = "/sys/kernel/debug/tracing/buffer_size_kb", + [CONTROL_GLOBAL_TRACING] = "/sys/kernel/debug/tracing/tracing_on" +}; + +/* + * Refresh callback for the control metrics; For traceppoints that have file + * based enabling we use gfs2_control_check_value(), for other metrics we + * call their corresponding "get" value. + */ +int +gfs2_control_fetch(int item, pmAtomValue *atom) +{ + if (item >= CONTROL_ALL && item <= CONTROL_GLOBAL_TRACING) { + atom->ul = gfs2_control_check_value(control_locations[item]); + + } else if (item == CONTROL_WORSTGLOCK) { + atom->ul = worst_glock_get_state(); + + } else if (item == CONTROL_LATENCY) { + atom->ul = latency_get_state(); + + } else if (item == CONTROL_FTRACE_GLOCK_THRESHOLD) { + atom->ul = ftrace_get_threshold(); + + } else { + return PM_ERR_PMID; + + } + return 1; +} + +/* + * Attempt open the enable file for the given filename and set the value + * contained in pmValueSet. The enable file for the tracepoint only accept + * 0 for disabled or 1 for enabled. + */ +int +gfs2_control_set_value(const char *filename, pmValueSet *vsp) +{ + FILE *fp; + int sts = 0; + int value = vsp->vlist[0].value.lval; + + if (strncmp(filename, control_locations[CONTROL_BUFFER_SIZE_KB], + sizeof(control_locations[CONTROL_BUFFER_SIZE_KB])-1) == 0) { + /* Special case for buffer_size_kb */ + if (value < 0 || value > 131072) /* Allow upto 128mb buffer per CPU */ + return - oserror(); + + } else if (value < 0 || value > 1) { + return -oserror(); + } + + fp = fopen(filename, "w"); + if (!fp) { + sts = -oserror(); /* EACCESS, File not found (stats not supported) */; + } else { + fprintf(fp, "%d\n", value); + fclose(fp); + } + return sts; +} + +/* + * We check the tracepoint enable file given by filename and return the value + * contained. This should either be 0 for disabled or 1 for enabled. In the + * event of permissions or file not found we will return zero. + */ +int +gfs2_control_check_value(const char *filename) +{ + FILE *fp; + char buffer[16]; + int value = 0; + + fp = fopen(filename, "r"); + if (fp) { + while (fgets(buffer, sizeof(buffer), fp) != NULL) + sscanf(buffer, "%d", &value); + fclose(fp); + } + return value; +} |