Revision c0cf4512a31eb3cec70b066bc36ed55f7d05b8c0 authored by Bart Van Assche on 23 June 2016, 07:35:48 UTC, committed by Doug Ledford on 23 June 2016, 16:04:09 UTC
The memory needed for the send and receive queues associated with a QP is proportional to the max_sge parameter. The current value of that parameter is such that with an mlx4 HCA the QP buffer size is 8 MB. Since DMA is used for communication between HCA and CPU that buffer either has to be allocated coherently or map_single() must succeed for that buffer. Since large contiguous allocations are fragile and since the maximum segment size for e.g. swiotlb is 256 KB, reduce the max_sge parameter. This patch avoids that the following text appears on the console after SRP logout and relogin on a system equipped with multiple IB HCAs: mlx4_core 0000:05:00.0: swiotlb buffer is full (sz: 8388608 bytes) swiotlb: coherent allocation failed for device 0000:05:00.0 size=8388608 CPU: 11 PID: 148 Comm: kworker/11:1 Not tainted 4.7.0-rc4-dbg+ #1 Call Trace: [<ffffffff812c6d35>] dump_stack+0x67/0x92 [<ffffffff812efe71>] swiotlb_alloc_coherent+0x141/0x150 [<ffffffff810458be>] x86_swiotlb_alloc_coherent+0x3e/0x50 [<ffffffffa03861fa>] mlx4_buf_direct_alloc.isra.5+0x9a/0x120 [mlx4_core] [<ffffffffa0386545>] mlx4_buf_alloc+0x165/0x1a0 [mlx4_core] [<ffffffffa035053d>] create_qp_common.isra.29+0x57d/0xff0 [mlx4_ib] [<ffffffffa03510da>] mlx4_ib_create_qp+0x12a/0x3f0 [mlx4_ib] [<ffffffffa031154a>] ib_create_qp+0x3a/0x250 [ib_core] [<ffffffffa055dd4b>] srpt_cm_handler+0x4bb/0xcad [ib_srpt] [<ffffffffa02c1ab0>] cm_process_work+0x20/0xf0 [ib_cm] [<ffffffffa02c3640>] cm_work_handler+0x1ac0/0x2059 [ib_cm] [<ffffffff810737ed>] process_one_work+0x19d/0x490 [<ffffffff81073b29>] worker_thread+0x49/0x490 [<ffffffff8107a0ea>] kthread+0xea/0x100 [<ffffffff815b25af>] ret_from_fork+0x1f/0x40 Fixes: b99f8e4d7bcd ("IB/srpt: convert to the generic RDMA READ/WRITE API") Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Doug Ledford <dledford@redhat.com>
1 parent 37e07cd
sg_pool.c
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/mempool.h>
#include <linux/slab.h>
#define SG_MEMPOOL_NR ARRAY_SIZE(sg_pools)
#define SG_MEMPOOL_SIZE 2
struct sg_pool {
size_t size;
char *name;
struct kmem_cache *slab;
mempool_t *pool;
};
#define SP(x) { .size = x, "sgpool-" __stringify(x) }
#if (SG_CHUNK_SIZE < 32)
#error SG_CHUNK_SIZE is too small (must be 32 or greater)
#endif
static struct sg_pool sg_pools[] = {
SP(8),
SP(16),
#if (SG_CHUNK_SIZE > 32)
SP(32),
#if (SG_CHUNK_SIZE > 64)
SP(64),
#if (SG_CHUNK_SIZE > 128)
SP(128),
#if (SG_CHUNK_SIZE > 256)
#error SG_CHUNK_SIZE is too large (256 MAX)
#endif
#endif
#endif
#endif
SP(SG_CHUNK_SIZE)
};
#undef SP
static inline unsigned int sg_pool_index(unsigned short nents)
{
unsigned int index;
BUG_ON(nents > SG_CHUNK_SIZE);
if (nents <= 8)
index = 0;
else
index = get_count_order(nents) - 3;
return index;
}
static void sg_pool_free(struct scatterlist *sgl, unsigned int nents)
{
struct sg_pool *sgp;
sgp = sg_pools + sg_pool_index(nents);
mempool_free(sgl, sgp->pool);
}
static struct scatterlist *sg_pool_alloc(unsigned int nents, gfp_t gfp_mask)
{
struct sg_pool *sgp;
sgp = sg_pools + sg_pool_index(nents);
return mempool_alloc(sgp->pool, gfp_mask);
}
/**
* sg_free_table_chained - Free a previously mapped sg table
* @table: The sg table header to use
* @first_chunk: was first_chunk not NULL in sg_alloc_table_chained?
*
* Description:
* Free an sg table previously allocated and setup with
* sg_alloc_table_chained().
*
**/
void sg_free_table_chained(struct sg_table *table, bool first_chunk)
{
if (first_chunk && table->orig_nents <= SG_CHUNK_SIZE)
return;
__sg_free_table(table, SG_CHUNK_SIZE, first_chunk, sg_pool_free);
}
EXPORT_SYMBOL_GPL(sg_free_table_chained);
/**
* sg_alloc_table_chained - Allocate and chain SGLs in an sg table
* @table: The sg table header to use
* @nents: Number of entries in sg list
* @first_chunk: first SGL
*
* Description:
* Allocate and chain SGLs in an sg table. If @nents@ is larger than
* SG_CHUNK_SIZE a chained sg table will be setup.
*
**/
int sg_alloc_table_chained(struct sg_table *table, int nents,
struct scatterlist *first_chunk)
{
int ret;
BUG_ON(!nents);
if (first_chunk) {
if (nents <= SG_CHUNK_SIZE) {
table->nents = table->orig_nents = nents;
sg_init_table(table->sgl, nents);
return 0;
}
}
ret = __sg_alloc_table(table, nents, SG_CHUNK_SIZE,
first_chunk, GFP_ATOMIC, sg_pool_alloc);
if (unlikely(ret))
sg_free_table_chained(table, (bool)first_chunk);
return ret;
}
EXPORT_SYMBOL_GPL(sg_alloc_table_chained);
static __init int sg_pool_init(void)
{
int i;
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct sg_pool *sgp = sg_pools + i;
int size = sgp->size * sizeof(struct scatterlist);
sgp->slab = kmem_cache_create(sgp->name, size, 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!sgp->slab) {
printk(KERN_ERR "SG_POOL: can't init sg slab %s\n",
sgp->name);
goto cleanup_sdb;
}
sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
sgp->slab);
if (!sgp->pool) {
printk(KERN_ERR "SG_POOL: can't init sg mempool %s\n",
sgp->name);
goto cleanup_sdb;
}
}
return 0;
cleanup_sdb:
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct sg_pool *sgp = sg_pools + i;
if (sgp->pool)
mempool_destroy(sgp->pool);
if (sgp->slab)
kmem_cache_destroy(sgp->slab);
}
return -ENOMEM;
}
static __exit void sg_pool_exit(void)
{
int i;
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct sg_pool *sgp = sg_pools + i;
mempool_destroy(sgp->pool);
kmem_cache_destroy(sgp->slab);
}
}
module_init(sg_pool_init);
module_exit(sg_pool_exit);
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