b5e8ad92c3
The new lockdep support for completions causeed the stack usage
in dm-integrity to explode, in case of write_journal from 504 bytes
to 1120 (using arm gcc-7.1.1):
drivers/md/dm-integrity.c: In function 'write_journal':
drivers/md/dm-integrity.c:827:1: error: the frame size of 1120 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
The problem is that not only the size of 'struct completion' grows
significantly, but we end up having multiple copies of it on the stack
when we assign it from a local variable after the initial declaration.
COMPLETION_INITIALIZER_ONSTACK() is the right thing to use when we
want to declare and initialize a completion on the stack. However,
this driver doesn't do that and instead initializes the completion
just before it is used.
In this case, init_completion() does the same thing more efficiently,
and drops the stack usage for the function above down to 496 bytes.
While the other functions in this file are not bad enough to cause
a warning, they benefit equally from the change, so I do the change
across the entire file. In the one place where we reuse a completion,
I picked the cheaper reinit_completion() over init_completion().
Fixes:
|
||
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.