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Subject: [PATCH 2/2] x86/e820: Use pr_debug to avoid spamming dmesg log with
 debug messages
From:   Heiner Kallweit <hkallweit1@gmail.com>
To:     Jason Baron <jbaron@akamai.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <f527618e-54f2-c2fb-e267-8065ac34e462@gmail.com>
Message-ID: <6d55670d-2f06-d768-699f-5a79cece6ce0@gmail.com>
Date:   Mon, 3 May 2021 21:40:30 +0200
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e820 emits quite some debug messages to the dmesg log. Let's restrict
this to cases where the debug output is actually requested. Switch to
pr_debug() for this purpose and make sure by checking the return code
that pr_cont() is only called if applicable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 arch/x86/kernel/e820.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index bc0657f0d..67ad4d8f0 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -465,6 +465,7 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_ty
 	u64 end;
 	unsigned int i;
 	u64 real_updated_size = 0;
+	int printed;
 
 	BUG_ON(old_type == new_type);
 
@@ -472,11 +473,13 @@ __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_ty
 		size = ULLONG_MAX - start;
 
 	end = start + size;
-	printk(KERN_DEBUG "e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
-	e820_print_type(old_type);
-	pr_cont(" ==> ");
-	e820_print_type(new_type);
-	pr_cont("\n");
+	printed = pr_debug("e820: update [mem %#010Lx-%#010Lx] ", start, end - 1);
+	if (printed > 0) {
+		e820_print_type(old_type);
+		pr_cont(" ==> ");
+		e820_print_type(new_type);
+		pr_cont("\n");
+	}
 
 	for (i = 0; i < table->nr_entries; i++) {
 		struct e820_entry *entry = &table->entries[i];
@@ -540,7 +543,7 @@ static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type o
 /* Remove a range of memory from the E820 table: */
 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 {
-	int i;
+	int printed, i;
 	u64 end;
 	u64 real_removed_size = 0;
 
@@ -548,10 +551,12 @@ u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool
 		size = ULLONG_MAX - start;
 
 	end = start + size;
-	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
-	if (check_type)
-		e820_print_type(old_type);
-	pr_cont("\n");
+	printed = pr_debug("e820: remove [mem %#010Lx-%#010Lx] ", start, end - 1);
+	if (printed > 0) {
+		if (check_type)
+			e820_print_type(old_type);
+		pr_cont("\n");
+	}
 
 	for (i = 0; i < e820_table->nr_entries; i++) {
 		struct e820_entry *entry = &e820_table->entries[i];
@@ -1230,7 +1235,7 @@ void __init e820__reserve_resources_late(void)
 		if (start >= end)
 			continue;
 
-		printk(KERN_DEBUG "e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
+		pr_debug("e820: reserve RAM buffer [mem %#010llx-%#010llx]\n", start, end);
 		reserve_region_with_split(&iomem_resource, start, end, "RAM buffer");
 	}
 }
-- 
2.31.1