[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250502032216.2312-3-dskmtsd@gmail.com>
Date: Fri, 2 May 2025 03:22:16 +0000
From: Daisuke Matsuda <dskmtsd@...il.com>
To: linux-kernel@...r.kernel.org,
linux-rdma@...r.kernel.org,
leon@...nel.org,
jgg@...pe.ca,
zyjzyj2000@...il.com
Cc: Daisuke Matsuda <dskmtsd@...il.com>
Subject: [PATCH for-next v1 2/2] RDMA/rxe: Enable asynchronous prefetch for ODP MRs
Calling ibv_advise_mr(3) with flags other than IBV_ADVISE_MR_FLAG_FLUSH
invokes asynchronous request. It is best-effort, and thus can safely be
deferred to the system-wide workqueue.
Signed-off-by: Daisuke Matsuda <dskmtsd@...il.com>
---
drivers/infiniband/sw/rxe/rxe_odp.c | 81 ++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c
index e5c60b061d7e..d98b385a18ce 100644
--- a/drivers/infiniband/sw/rxe/rxe_odp.c
+++ b/drivers/infiniband/sw/rxe/rxe_odp.c
@@ -425,6 +425,73 @@ enum resp_states rxe_odp_do_atomic_write(struct rxe_mr *mr, u64 iova, u64 value)
return RESPST_NONE;
}
+struct prefetch_mr_work {
+ struct work_struct work;
+ u32 pf_flags;
+ u32 num_sge;
+ struct {
+ u64 io_virt;
+ struct rxe_mr *mr;
+ size_t length;
+ } frags[];
+};
+
+static void rxe_ib_prefetch_mr_work(struct work_struct *w)
+{
+ struct prefetch_mr_work *work =
+ container_of(w, struct prefetch_mr_work, work);
+ int ret;
+ u32 i;
+
+ /* We rely on IB/core that work is executed if we have num_sge != 0 only. */
+ WARN_ON(!work->num_sge);
+ for (i = 0; i < work->num_sge; ++i) {
+ struct ib_umem_odp *umem_odp;
+
+ ret = rxe_odp_do_pagefault_and_lock(work->frags[i].mr, work->frags[i].io_virt,
+ work->frags[i].length, work->pf_flags);
+ if (ret < 0) {
+ rxe_dbg_mr(work->frags[i].mr, "failed to prefetch the mr\n");
+ continue;
+ }
+
+ umem_odp = to_ib_umem_odp(work->frags[i].mr->umem);
+ mutex_unlock(&umem_odp->umem_mutex);
+ }
+
+ kvfree(work);
+}
+
+static int rxe_init_prefetch_work(struct ib_pd *ibpd,
+ enum ib_uverbs_advise_mr_advice advice,
+ u32 pf_flags, struct prefetch_mr_work *work,
+ struct ib_sge *sg_list, u32 num_sge)
+{
+ struct rxe_pd *pd = container_of(ibpd, struct rxe_pd, ibpd);
+ u32 i;
+
+ INIT_WORK(&work->work, rxe_ib_prefetch_mr_work);
+ work->pf_flags = pf_flags;
+
+ for (i = 0; i < num_sge; ++i) {
+ struct rxe_mr *mr;
+
+ mr = lookup_mr(pd, IB_ACCESS_LOCAL_WRITE,
+ sg_list[i].lkey, RXE_LOOKUP_LOCAL);
+ if (IS_ERR(mr)) {
+ work->num_sge = i;
+ return PTR_ERR(mr);
+ }
+ work->frags[i].io_virt = sg_list[i].addr;
+ work->frags[i].length = sg_list[i].length;
+ work->frags[i].mr = mr;
+
+ rxe_put(mr);
+ }
+ work->num_sge = num_sge;
+ return 0;
+}
+
static int rxe_ib_prefetch_sg_list(struct ib_pd *ibpd,
enum ib_uverbs_advise_mr_advice advice,
u32 pf_flags, struct ib_sge *sg_list,
@@ -478,6 +545,8 @@ static int rxe_ib_advise_mr_prefetch(struct ib_pd *ibpd,
u32 flags, struct ib_sge *sg_list, u32 num_sge)
{
u32 pf_flags = RXE_PAGEFAULT_DEFAULT;
+ struct prefetch_mr_work *work;
+ int rc;
if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH)
pf_flags |= RXE_PAGEFAULT_RDONLY;
@@ -490,7 +559,17 @@ static int rxe_ib_advise_mr_prefetch(struct ib_pd *ibpd,
return rxe_ib_prefetch_sg_list(ibpd, advice, pf_flags, sg_list,
num_sge);
- /* Asynchronous call is "best-effort" */
+ /* Asynchronous call is "best-effort" and allowed to fail */
+ work = kvzalloc(struct_size(work, frags, num_sge), GFP_KERNEL);
+ if (!work)
+ return -ENOMEM;
+
+ rc = rxe_init_prefetch_work(ibpd, advice, pf_flags, work, sg_list, num_sge);
+ if (rc) {
+ kvfree(work);
+ return rc;
+ }
+ queue_work(system_unbound_wq, &work->work);
return 0;
}
--
2.43.0
Powered by blists - more mailing lists