5233c47c8d
commit a666e5c05e7c4aaabb2c5d58117b0946803d03d2 upstream. The system would deadlock when swapping to a dm-crypt device. The reason is that for each incoming write bio, dm-crypt allocates memory that holds encrypted data. These excessive allocations exhaust all the memory and the result is either deadlock or OOM trigger. This patch limits the number of in-flight swap bios, so that the memory consumed by dm-crypt is limited. The limit is enforced if the target set the "limit_swap_bios" variable and if the bio has REQ_SWAP set. Non-swap bios are not affected becuase taking the semaphore would cause performance degradation. This is similar to request-based drivers - they will also block when the number of requests is over the limit. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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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.