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 Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Yuntao Wang <ytcoode@xxxxxxxxx> 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@xxxxxxxxx Signed-off-by: Yuntao Wang <ytcoode@xxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Dave Young <dyoung@xxxxxxxxxx> Cc: Hari Bathini <hbathini@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Sean Christopherson <seanjc@xxxxxxxxxx> Cc: Takashi Iwai <tiwai@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- 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@xxxxxxxxx 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