+ crash_core-optimize-crash_exclude_mem_range.patch added to mm-nonmm-unstable branch

+ crash_core-optimize-crash_exclude_mem_range.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: crash_core: optimize crash_exclude_mem_range()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     crash_core-optimize-crash_exclude_mem_range.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/crash_core-optimize-crash_exclude_mem_range.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Yuntao Wang <ytcoode@gmail.com>
Subject: crash_core: optimize crash_exclude_mem_range()
Date: Wed, 20 Dec 2023 00:34:18 +0800

Because memory ranges in mem->ranges are stored in ascending order, when
we detect `p_end < start`, we can break the for loop early, as the
subsequent memory ranges must also be outside the range we are looking
for.

Link: https://lkml.kernel.org/r/20231219163418.108591-1-ytcoode@gmail.com
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/crash_core.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/kernel/crash_core.c~crash_core-optimize-crash_exclude_mem_range
+++ a/kernel/crash_core.c
@@ -575,9 +575,12 @@ int crash_exclude_mem_range(struct crash
 		p_start = mstart;
 		p_end = mend;
 
-		if (p_start > end || p_end < start)
+		if (p_start > end)
 			continue;
 
+		if (p_end < start)
+			break;
+
 		/* Truncate any area outside of range */
 		if (p_start < start)
 			p_start = start;
_

Patches currently in -mm which might be from ytcoode@gmail.com are

kexec-use-align-macro-instead-of-open-coding-it.patch
x86-kexec-simplify-the-logic-of-mem_region_callback.patch
x86-crash-remove-the-unused-image-parameter-from-prepare_elf_headers.patch
x86-crash-use-sz_1m-macro-instead-of-hardcoded-value.patch
crash_core-fix-and-simplify-the-logic-of-crash_exclude_mem_range.patch
x86-crash-fix-potential-cmem-ranges-array-overflow.patch
crash_core-optimize-crash_exclude_mem_range.patch
kexec-modify-the-meaning-of-the-end-parameter-in-kimage_is_destination_range.patch
kexec_file-fix-incorrect-temp_start-value-in-locate_mem_hole_top_down.patch