diff options
| author | Li RongQing <lirongqing@baidu.com> | 2025-11-26 10:51:47 +0800 |
|---|---|---|
| committer | Leon Romanovsky <leon@kernel.org> | 2025-11-26 03:15:36 -0500 |
| commit | f37e2868792335f2e8bbdcc02ebbb4830453f83c (patch) | |
| tree | 5766bccca5963407d78133f2ba3a5500fe679735 | |
| parent | 01dad9ca37c60d08f71e2ef639875ae895deede6 (diff) | |
RDMA/core: Reduce cond_resched() frequency in __ib_umem_release
The current implementation calls cond_resched() for every SG entry
in __ib_umem_release(), which can increase needless overhead.
This patch introduces RESCHED_LOOP_CNT_THRESHOLD (0x1000) to limit
how often cond_resched() is called. The function now yields the CPU
once every 4096 iterations, and yield at the very first iteration
for lots of small umem case, to reduce scheduling overhead.
Fixes: d056bc45b62b ("RDMA/core: Prevent soft lockup during large user memory region cleanup")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://patch.msgid.link/20251126025147.2627-1-lirongqing@baidu.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
| -rw-r--r-- | drivers/infiniband/core/umem.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 8fd84aa37289..8137031c2a65 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -45,6 +45,8 @@ #include "uverbs.h" +#define RESCHED_LOOP_CNT_THRESHOLD 0x1000 + static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) { bool make_dirty = umem->writable && dirty; @@ -58,7 +60,9 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i) { unpin_user_page_range_dirty_lock(sg_page(sg), DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty); - cond_resched(); + + if (i && !(i % RESCHED_LOOP_CNT_THRESHOLD)) + cond_resched(); } sg_free_append_table(&umem->sgt_append); |