From bd23024b9774e681cbe6cc3afcb24244dfcb2390 Mon Sep 17 00:00:00 2001 From: Tomas Mudrunka Date: Tue, 21 Mar 2023 11:34:30 +0100 Subject: 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 Cc: Jonathan Corbet Cc: Mike Rapoport (IBM) Signed-off-by: Andrew Morton --- mm/memtest.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'mm/memtest.c') diff --git a/mm/memtest.c b/mm/memtest.c index f53ace709ccd..57149dfee438 100644 --- a/mm/memtest.c +++ b/mm/memtest.c @@ -4,6 +4,9 @@ #include #include +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) -- cgit v1.2.3-70-g09d2