prefetch_io.d revision 479ad5c2b44df79e321ef43d6f6e53bb3edab663
#!/usr/sbin/dtrace -Cs
/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright (c) 2015, 2016 by Delphix. All rights reserved.
*/
/*
* prefetch_ios: Number of IOs the prefetcher issued
* @c["prefetched_demand_reads"]: Number of demand reads already prefetched
* @c["sync_wait_for_async"]: Number of times sync IO waited for prefetch IO
* @s["demand"]: Number of non-prefetch read IOs
* @s["logical"]: Logical (uncompressed) bytes read per interval
* @s["physical"]: Physical (compressed) bytes read per interval
*/
#pragma D option aggsortkey
#pragma D option quiet
#define SPA_MINBLOCKSHIFT 9
#define ARC_FLAGS_PREFETCH (1 << 3)
#define HDR_GET_LSIZE(hdr) ((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
#define HDR_GET_PSIZE(hdr) ((hdr)->b_psize << SPA_MINBLOCKSHIFT)
BEGIN
{
prefetch_ios = `arc_stats.arcstat_prefetch_data_misses.value.ui64;
prefetch_ios += `arc_stats.arcstat_prefetch_metadata_misses.value.ui64;
@s["demand"] = sum(0);
@s["logical"] = sum(0);
@s["physical"] = sum(0);
@c["prefetched_demand_reads"] = count();
@c["sync_wait_for_async"] = count();
clear(@s);
clear(@c);
}
arc_read:arc-demand-hit-predictive-prefetch
{
@c["prefetched_demand_reads"] = count();
}
arc_read:arc-sync-wait-for-async
{
@c["sync_wait_for_async"] = count();
}
arc_read_done:entry
/ args[0]->io_spa->spa_name == $$1 /
{
this->zio = args[0];
this->hdr = (arc_buf_hdr_t *)this->zio->io_private;
@s["demand"] = sum(this->hdr->b_flags & ARC_FLAGS_PREFETCH ? 0 : 1);
@s["logical"] = sum(HDR_GET_LSIZE(this->hdr));
@s["physical"] = sum(HDR_GET_PSIZE(this->hdr));
}
tick-$2s
{
this->new_prefetch_ios =
`arc_stats.arcstat_prefetch_data_misses.value.ui64 +
`arc_stats.arcstat_prefetch_metadata_misses.value.ui64;
printf("%u\n%-24s\t%u\n", `time, "prefetch_ios",
this->new_prefetch_ios - prefetch_ios);
printa("%-24s\t%@u\n", @s);
printa("%-24s\t%@u\n", @c);
prefetch_ios = this->new_prefetch_ios;
clear(@s);
clear(@c);
}
ERROR
{
trace(arg1);
trace(arg2);
trace(arg3);
trace(arg4);
trace(arg5);
}