mm/memtest: add results of early memtest to /proc/meminfo
Currently the memtest results were only presented in dmesg.
When running a large fleet of devices without ECC RAM it's currently not
easy to do bulk monitoring for memory corruption. You have to parse
dmesg, but that's a ring buffer so the error might disappear after some
time. In general I do not consider dmesg to be a great API to query RAM
status.
In several companies I've seen such errors remain undetected and cause
issues for way too long. So I think it makes sense to provide a
monitoring API, so that we can safely detect and act upon them.
This adds /proc/meminfo entry which can be easily used by scripts.
Link: https://lkml.kernel.org/r/20230321103430.7130-1-tomas.mudrunka@gmail.com
Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/memtest.c b/mm/memtest.c
index f53ace7..57149df 100644
--- a/mm/memtest.c
+++ b/mm/memtest.c
@@ -4,6 +4,9 @@
#include <linux/init.h>
#include <linux/memblock.h>
+bool early_memtest_done;
+phys_addr_t early_memtest_bad_size;
+
static u64 patterns[] __initdata = {
/* The first entry has to be 0 to leave memtest with zeroed memory */
0,
@@ -30,6 +33,7 @@ static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr
pr_info(" %016llx bad mem addr %pa - %pa reserved\n",
cpu_to_be64(pattern), &start_bad, &end_bad);
memblock_reserve(start_bad, end_bad - start_bad);
+ early_memtest_bad_size += (end_bad - start_bad);
}
static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
@@ -61,6 +65,8 @@ static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size
}
if (start_bad)
reserve_bad_mem(pattern, start_bad, last_bad + incr);
+
+ early_memtest_done = true;
}
static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
