linux-kernel - [PATCH] x86/mce: Increase the size of the MCE pool from 2 to 8 pages

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Date:   Wed, 11 Oct 2023 16:33:20 +0000
From:   Filippo Sironi <sironi@...zon.de>
To:     <linux-kernel@...r.kernel.org>
CC:     <sironi@...zon.de>, <tony.luck@...el.com>, <bp@...en8.de>,
        <tglx@...utronix.de>, <mingo@...hat.com>,
        <dave.hansen@...ux.intel.com>, <x86@...nel.org>, <hpa@...or.com>,
        <linux-edac@...r.kernel.org>
Subject: [PATCH] x86/mce: Increase the size of the MCE pool from 2 to 8 pages

On some of our large servers and some of our most sorry servers ( :) ),
we're seeing the kernel reporting the warning in mce_gen_pool_add: "MCE
records pool full!". Let's increase the amount of memory that we use to
store the MCE records from 2 to 8 pages to prevent this from happening
and be able to collect useful information.

Signed-off-by: Filippo Sironi <sironi@...zon.de>
---
 arch/x86/kernel/cpu/mce/genpool.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/genpool.c b/arch/x86/kernel/cpu/mce/genpool.c
index fbe8b61c3413..870dcb7011cd 100644
--- a/arch/x86/kernel/cpu/mce/genpool.c
+++ b/arch/x86/kernel/cpu/mce/genpool.c
@@ -17,9 +17,9 @@
  *
  * This memory pool is only to be used to save MCE records in MCE context.
  * MCE events are rare, so a fixed size memory pool should be enough. Use
- * 2 pages to save MCE events for now (~80 MCE records at most).
+ * 8 pages to save MCE events for now (~320 MCE records at most).
  */
-#define MCE_POOLSZ	(2 * PAGE_SIZE)
+#define MCE_POOLSZ	(8 * PAGE_SIZE)

 static struct gen_pool *mce_evt_pool;
 static LLIST_HEAD(mce_event_llist);
-- 
2.33.0

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