From a293aba4a584709889f77a0ad0c45746aecf1b9f Mon Sep 17 00:00:00 2001 From: Martin Liu Date: Sat, 8 Mar 2025 03:46:01 +0000 Subject: 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 Acked-by: David Rientjes Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Steven Rostedt Signed-off-by: Andrew Morton --- mm/page_alloc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm/page_alloc.c') 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]); } } } -- cgit