6.6-stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche bvanassche@acm.org
[ Upstream commit 4d784c042d164f10fc809e2338457036cd7c653d ]
Since commit 4c39529663b9 ("slab: Warn on duplicate cache names when DEBUG_VM=y"), slab complains about duplicate cache names. Hence this patch. The approach is as follows: - Maintain an xarray with the slab size as index and a reference count and a kmem_cache pointer as contents. Use srpt-${slab_size} as kmem cache name. - Use 512-byte alignment for all slabs instead of only for some of the slabs. - Increment the reference count instead of calling kmem_cache_create(). - Decrement the reference count instead of calling kmem_cache_destroy().
Fixes: 5dabcd0456d7 ("RDMA/srpt: Add support for immediate data") Link: https://patch.msgid.link/r/20241009210048.4122518-1-bvanassche@acm.org Reported-by: Shinichiro Kawasaki shinichiro.kawasaki@wdc.com Closes: https://lore.kernel.org/linux-block/xpe6bea7rakpyoyfvspvin2dsozjmjtjktpph7re... Suggested-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Bart Van Assche bvanassche@acm.org Tested-by: Shin'ichiro Kawasaki shinichiro.kawasaki@wdc.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/ulp/srpt/ib_srpt.c | 80 +++++++++++++++++++++++---- 1 file changed, 68 insertions(+), 12 deletions(-)
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 45547bf281e31..4bebc34a2929b 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -68,6 +68,8 @@ MODULE_LICENSE("Dual BSD/GPL"); static u64 srpt_service_guid; static DEFINE_SPINLOCK(srpt_dev_lock); /* Protects srpt_dev_list. */ static LIST_HEAD(srpt_dev_list); /* List of srpt_device structures. */ +static DEFINE_MUTEX(srpt_mc_mutex); /* Protects srpt_memory_caches. */ +static DEFINE_XARRAY(srpt_memory_caches); /* See also srpt_memory_cache_entry */
static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE; module_param(srp_max_req_size, int, 0444); @@ -105,6 +107,63 @@ static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc); static void srpt_send_done(struct ib_cq *cq, struct ib_wc *wc); static void srpt_process_wait_list(struct srpt_rdma_ch *ch);
+/* Type of the entries in srpt_memory_caches. */ +struct srpt_memory_cache_entry { + refcount_t ref; + struct kmem_cache *c; +}; + +static struct kmem_cache *srpt_cache_get(unsigned int object_size) +{ + struct srpt_memory_cache_entry *e; + char name[32]; + void *res; + + guard(mutex)(&srpt_mc_mutex); + e = xa_load(&srpt_memory_caches, object_size); + if (e) { + refcount_inc(&e->ref); + return e->c; + } + snprintf(name, sizeof(name), "srpt-%u", object_size); + e = kmalloc(sizeof(*e), GFP_KERNEL); + if (!e) + return NULL; + refcount_set(&e->ref, 1); + e->c = kmem_cache_create(name, object_size, /*align=*/512, 0, NULL); + if (!e->c) + goto free_entry; + res = xa_store(&srpt_memory_caches, object_size, e, GFP_KERNEL); + if (xa_is_err(res)) + goto destroy_cache; + return e->c; + +destroy_cache: + kmem_cache_destroy(e->c); + +free_entry: + kfree(e); + return NULL; +} + +static void srpt_cache_put(struct kmem_cache *c) +{ + struct srpt_memory_cache_entry *e = NULL; + unsigned long object_size; + + guard(mutex)(&srpt_mc_mutex); + xa_for_each(&srpt_memory_caches, object_size, e) + if (e->c == c) + break; + if (WARN_ON_ONCE(!e)) + return; + if (!refcount_dec_and_test(&e->ref)) + return; + WARN_ON_ONCE(xa_erase(&srpt_memory_caches, object_size) != e); + kmem_cache_destroy(e->c); + kfree(e); +} + /* * The only allowed channel state changes are those that change the channel * state into a state with a higher numerical value. Hence the new > prev test. @@ -2119,13 +2178,13 @@ static void srpt_release_channel_work(struct work_struct *w) ch->sport->sdev, ch->rq_size, ch->rsp_buf_cache, DMA_TO_DEVICE);
- kmem_cache_destroy(ch->rsp_buf_cache); + srpt_cache_put(ch->rsp_buf_cache);
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring, sdev, ch->rq_size, ch->req_buf_cache, DMA_FROM_DEVICE);
- kmem_cache_destroy(ch->req_buf_cache); + srpt_cache_put(ch->req_buf_cache);
kref_put(&ch->kref, srpt_free_ch); } @@ -2245,8 +2304,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, INIT_LIST_HEAD(&ch->cmd_wait_list); ch->max_rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
- ch->rsp_buf_cache = kmem_cache_create("srpt-rsp-buf", ch->max_rsp_size, - 512, 0, NULL); + ch->rsp_buf_cache = srpt_cache_get(ch->max_rsp_size); if (!ch->rsp_buf_cache) goto free_ch;
@@ -2280,8 +2338,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, alignment_offset = round_up(imm_data_offset, 512) - imm_data_offset; req_sz = alignment_offset + imm_data_offset + srp_max_req_size; - ch->req_buf_cache = kmem_cache_create("srpt-req-buf", req_sz, - 512, 0, NULL); + ch->req_buf_cache = srpt_cache_get(req_sz); if (!ch->req_buf_cache) goto free_rsp_ring;
@@ -2478,7 +2535,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, ch->req_buf_cache, DMA_FROM_DEVICE);
free_recv_cache: - kmem_cache_destroy(ch->req_buf_cache); + srpt_cache_put(ch->req_buf_cache);
free_rsp_ring: srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring, @@ -2486,7 +2543,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev, ch->rsp_buf_cache, DMA_TO_DEVICE);
free_rsp_cache: - kmem_cache_destroy(ch->rsp_buf_cache); + srpt_cache_put(ch->rsp_buf_cache);
free_ch: if (rdma_cm_id) @@ -3055,7 +3112,7 @@ static void srpt_free_srq(struct srpt_device *sdev) srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev, sdev->srq_size, sdev->req_buf_cache, DMA_FROM_DEVICE); - kmem_cache_destroy(sdev->req_buf_cache); + srpt_cache_put(sdev->req_buf_cache); sdev->srq = NULL; }
@@ -3082,8 +3139,7 @@ static int srpt_alloc_srq(struct srpt_device *sdev) pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n", sdev->srq_size, sdev->device->attrs.max_srq_wr, dev_name(&device->dev));
- sdev->req_buf_cache = kmem_cache_create("srpt-srq-req-buf", - srp_max_req_size, 0, 0, NULL); + sdev->req_buf_cache = srpt_cache_get(srp_max_req_size); if (!sdev->req_buf_cache) goto free_srq;
@@ -3105,7 +3161,7 @@ static int srpt_alloc_srq(struct srpt_device *sdev) return 0;
free_cache: - kmem_cache_destroy(sdev->req_buf_cache); + srpt_cache_put(sdev->req_buf_cache);
free_srq: ib_destroy_srq(srq);