diff options
| author | Martin Liu <liumartin@google.com> | 2025-03-08 03:46:00 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-17 22:07:02 -0700 |
| commit | 8c02048d1c6126527f15752a5e0849dc49cefeeb (patch) | |
| tree | 2204afef44c99f4a01d4c62b3409318c3e4e269d /include/trace | |
| parent | mm/shmem: fix functions documentation (diff) | |
| download | linux-8c02048d1c6126527f15752a5e0849dc49cefeeb.tar.gz linux-8c02048d1c6126527f15752a5e0849dc49cefeeb.zip | |
mm/page_alloc: add trace event for per-zone watermark setup
Patch series "Add tracepoints for lowmem reserves, watermarks and
totalreserve_pages", v2.
This patchset introduces tracepoints to track changes in the lowmem
reserves, watermarks and totalreserve_pages. This helps to track
the exact timing of such changes and understand their relation to
reclaim activities.
The tracepoints added are:
mm_setup_per_zone_lowmem_reserve
mm_setup_per_zone_wmarks
mm_calculate_totalreserve_pagesi
This patch (of 3):
This commit introduces the `mm_setup_per_zone_wmarks` trace event,
which provides detailed insights into the kernel's per-zone watermark
configuration, offering precise timing and the ability to correlate
watermark changes with specific kernel events.
While `/proc/zoneinfo` provides some information about zone watermarks,
this trace event offers:
1. The ability to link watermark changes to specific kernel events and
logic.
2. The ability to capture rapid or short-lived changes in watermarks
that may be missed by user-space polling
3. Diagnosing unexpected kswapd activity or excessive direct reclaim
triggered by rapidly changing watermarks.
Link: https://lkml.kernel.org/r/20250308034606.2036033-1-liumartin@google.com
Link: https://lkml.kernel.org/r/20250308034606.2036033-2-liumartin@google.com
Signed-off-by: Martin Liu <liumartin@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Martin Liu <liumartin@google.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/kmem.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index b37eb0a7060f..5fd392dae503 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -342,6 +342,39 @@ TRACE_EVENT(mm_alloc_contig_migrate_range_info, __entry->nr_mapped) ); +TRACE_EVENT(mm_setup_per_zone_wmarks, + + TP_PROTO(struct zone *zone), + + TP_ARGS(zone), + + TP_STRUCT__entry( + __field(int, node_id) + __string(name, zone->name) + __field(unsigned long, watermark_min) + __field(unsigned long, watermark_low) + __field(unsigned long, watermark_high) + __field(unsigned long, watermark_promo) + ), + + TP_fast_assign( + __entry->node_id = zone->zone_pgdat->node_id; + __assign_str(name); + __entry->watermark_min = zone->_watermark[WMARK_MIN]; + __entry->watermark_low = zone->_watermark[WMARK_LOW]; + __entry->watermark_high = zone->_watermark[WMARK_HIGH]; + __entry->watermark_promo = zone->_watermark[WMARK_PROMO]; + ), + + TP_printk("node_id=%d zone name=%s watermark min=%lu low=%lu high=%lu promo=%lu", + __entry->node_id, + __get_str(name), + __entry->watermark_min, + __entry->watermark_low, + __entry->watermark_high, + __entry->watermark_promo) +); + /* * Required for uniquely and securely identifying mm in rss_stat tracepoint. */ |