d64c7dbb4d
In xmon we have two variables that are used by the dump commands. There's ndump which is the number of bytes to dump using 'd', and nidump which is the number of instructions to dump using 'di'. ndump starts as 64 and nidump starts as 16, but both can be set by the user. It's fairly common to be pasting addresses into xmon when trying to debug something, and if you inadvertently double paste an address like so: 0:mon> di c000000002101f6c c000000002101f6c The second value is interpreted as the number of instructions to dump. Luckily it doesn't dump 13 quintrillion instructions, the value is limited to MAX_DUMP (128K). But as each instruction is dumped on a single line, that's still a lot of output. If you're on a slow console that can take multiple minutes to print. If you were "just popping in and out of xmon quickly before the RCU/hardlockup detector fires" you are now having a bad day. Things are not as bad with 'd' because we print 16 bytes per line, so it's fewer lines. But it's still quite a lot. So shrink the maximum for 'd' to 64K (one page), which is 4096 lines. For 'di' add a new limit which is the above / 4 - because instructions are 4 bytes, meaning again we can dump one page. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200219110007.31195-1-mpe@ellerman.id.au |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.