Re: [PATCH 1/2 v4] kdump: add the vmcoreinfo documentation
From: lijiang <hidden>
Date: 2019-01-04 02:28:33
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在 2019年01月04日 03:28, Kazuhito Hagio 写道:
Hi Lianbo, -----Original Message-----quoted
+======================= +What is the VMCOREINFO? +======================= + +VMCOREINFO is a special ELF note section. It contains various +information from the kernel like structure size, page size, symbol +values, field offsets, etc. These data are packed into an ELF note +section and used by user-space tools like crash and makedumpfile to +analyze a kernel's memory layout. + +To dump the VMCOREINFO contents, one can do: + +# makedumpfile -g VMCOREINFO -x vmlinuxagain, this command does not dump the VMCOREINFO in ELF note section. It converts the vmlinux's debug infomation into a VMCOREINFO-like data. So I don't think this command is suitable to introduce here.
Thank you, Kazu. As you mentioned, makedumpfile in 'devel' branch can print VMCOREINFO in /proc/kcore, can i add the following command to this document? #makedumpfile --mem-usage /proc/kcore -D
quoted
+PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab| +PG_hwpoision|PG_head_mask +----------------------------------------------------- + +Page attributes. These flags are used to filter free pages.Some of these are not used to filter *free* pages, so ... used to filter various unnecessary pages.
Great. I will modify it in next post. And also merge the 'PG_buddy' and 'PG_offline' into the PG_* flag here. Many thanks. Lianbo
quoted
+PAGE_BUDDY_MAPCOUNT_VALUE or ~PG_buddy +--------------------------------------then, this can be merged into the one above?quoted
+====== +x86_64 +======...quoted
+PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline) +----------------------------------------This looks not only for x86_64, and also can be merged into the PG_* flags? Thank you for your effort! Kazu