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| author |   Martin Liu <liumartin@google.com> | 2025-03-08 03:46:01 +0000 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2025-03-17 22:07:03 -0700 |
| commit | a293aba4a584709889f77a0ad0c45746aecf1b9f (patch) | |
| tree | 47ee6e6d8b000b13ac38a3f185a1e04ea43cfe84 | |
| parent | mm/page_alloc: add trace event for per-zone watermark setup (diff) | |
| download | wireguard-linux-a293aba4a584709889f77a0ad0c45746aecf1b9f.tar.xz wireguard-linux-a293aba4a584709889f77a0ad0c45746aecf1b9f.zip | |
mm/page_alloc: add trace event for per-zone lowmem reserve setup
This commit introduces the `mm_setup_per_zone_lowmem_reserve` trace
event,which provides detailed insights into the kernel's per-zone lowmem
reserve configuration.
The trace event provides precise timestamps, allowing developers to
1. Correlate lowmem reserve changes with specific kernel events and
able to diagnose unexpected kswapd or direct reclaim behavior triggered
by dynamic changes in lowmem reserve.
2. Know memory allocation failures that occur due to insufficient
lowmem reserve, by precisely correlating allocation attempts with
reserve adjustments.
Link: https://lkml.kernel.org/r/20250308034606.2036033-3-liumartin@google.com
Signed-off-by: Martin Liu <liumartin@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/trace/events/kmem.h | 27 | ||||
| -rw-r--r-- | mm/page_alloc.c | 2 |
2 files changed, 29 insertions, 0 deletions
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index 5fd392dae503..9623e68d4d26 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -375,6 +375,33 @@ TRACE_EVENT(mm_setup_per_zone_wmarks, __entry->watermark_promo) ); +TRACE_EVENT(mm_setup_per_zone_lowmem_reserve, + + TP_PROTO(struct zone *zone, struct zone *upper_zone, long lowmem_reserve), + + TP_ARGS(zone, upper_zone, lowmem_reserve), + + TP_STRUCT__entry( + __field(int, node_id) + __string(name, zone->name) + __string(upper_name, upper_zone->name) + __field(long, lowmem_reserve) + ), + + TP_fast_assign( + __entry->node_id = zone->zone_pgdat->node_id; + __assign_str(name); + __assign_str(upper_name); + __entry->lowmem_reserve = lowmem_reserve; + ), + + TP_printk("node_id=%d zone name=%s upper_zone name=%s lowmem_reserve_pages=%ld", + __entry->node_id, + __get_str(name), + __get_str(upper_name), + __entry->lowmem_reserve) +); + /* * Required for uniquely and securely identifying mm in rss_stat tracepoint. */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b739367434ce..a82d96cb3044 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5943,6 +5943,8 @@ static void setup_per_zone_lowmem_reserve(void) zone->lowmem_reserve[j] = 0; else zone->lowmem_reserve[j] = managed_pages / ratio; + trace_mm_setup_per_zone_lowmem_reserve(zone, upper_zone, + zone->lowmem_reserve[j]); } } } |