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A mirror of the official Linux kernel repository just in case
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Waiting for activity on the "clean_list" to quiesce is no substitute for proper locking. We can have multiple threads competing for "llist_del_first" via "rds_ib_reuse_mr", and a single thread competing for "llist_del_all" and "llist_del_first" via "rds_ib_flush_mr_pool". Since "llist_del_first" depends on "list->first->next" not to change in the midst of the operation, simply waiting for all current calls to "rds_ib_reuse_mr" to quiesce across all CPUs is woefully inadequate: By the time "wait_clean_list_grace" is done iterating over all CPUs to see that there is no concurrent caller to "rds_ib_reuse_mr", a new caller may have just shown up on the first CPU. Furthermore, <linux/llist.h> explicitly calls out the need for locking: * Cases where locking is needed: * If we have multiple consumers with llist_del_first used in one consumer, * and llist_del_first or llist_del_all used in other consumers, * then a lock is needed. Also, while at it, drop the unused "pool" parameter from "list_to_llist_nodes". Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
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 |
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.