diff options
| author | Bob Pearson <rpearsonhpe@gmail.com> | 2022-06-30 22:04:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-25 12:45:45 +0300 |
| commit | 0a5e36832ffd96f08fb6b39e7e61c835b3186c1b (patch) | |
| tree | a9455e0b5f474ff15bd4da05f581fc150da08635 /drivers/infiniband/sw/rxe/rxe_task.c | |
| parent | f03d253ba71994b196f342a7acad448a56812a8c (diff) | |
| download | linux-0a5e36832ffd96f08fb6b39e7e61c835b3186c1b.tar.xz | |
RDMA/rxe: Limit the number of calls to each tasklet
[ Upstream commit eff6d998ca297cb0b2e53b032a56cf8e04dd8b17 ]
Limit the maximum number of calls to each tasklet from rxe_do_task()
before yielding the cpu. When the limit is reached reschedule the tasklet
and exit the calling loop. This patch prevents one tasklet from consuming
100% of a cpu core and causing a deadlock or soft lockup.
Link: https://lore.kernel.org/r/20220630190425.2251-9-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/infiniband/sw/rxe/rxe_task.c')
| -rw-r--r-- | drivers/infiniband/sw/rxe/rxe_task.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c index 0c4db5bb17d7..2248cf33d776 100644 --- a/drivers/infiniband/sw/rxe/rxe_task.c +++ b/drivers/infiniband/sw/rxe/rxe_task.c @@ -8,7 +8,7 @@ #include <linux/interrupt.h> #include <linux/hardirq.h> -#include "rxe_task.h" +#include "rxe.h" int __rxe_do_task(struct rxe_task *task) @@ -33,6 +33,7 @@ void rxe_do_task(struct tasklet_struct *t) int cont; int ret; struct rxe_task *task = from_tasklet(task, t, tasklet); + unsigned int iterations = RXE_MAX_ITERATIONS; spin_lock_bh(&task->state_lock); switch (task->state) { @@ -61,13 +62,20 @@ void rxe_do_task(struct tasklet_struct *t) spin_lock_bh(&task->state_lock); switch (task->state) { case TASK_STATE_BUSY: - if (ret) + if (ret) { task->state = TASK_STATE_START; - else + } else if (iterations--) { cont = 1; + } else { + /* reschedule the tasklet and exit + * the loop to give up the cpu + */ + tasklet_schedule(&task->tasklet); + task->state = TASK_STATE_START; + } break; - /* soneone tried to run the task since the last time we called + /* someone tried to run the task since the last time we called * func, so we will call one more time regardless of the * return value */ |