Revision 72f961320d5d15bfcb26dbe3edaa3f7d25fd2c8a authored by Paolo Abeni on 10 June 2021, 22:59:40 UTC, committed by David S. Miller on 10 June 2021, 23:47:44 UTC
If the host is under sever memory pressure, and RX forward memory allocation for the msk fails, we try to borrow the required memory from the ingress subflow. The current attempt is a bit flaky: if skb->truesize is less than SK_MEM_QUANTUM, the ssk will not release any memory, and the next schedule will fail again. Instead, directly move the required amount of pages from the ssk to the msk, if available Fixes: 9c3f94e1681b ("mptcp: add missing memory scheduling in the rx path") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 22488e4
sg_pool.c
// SPDX-License-Identifier: GPL-2.0-only
#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
* @nents_first_chunk: size of the first_chunk SGL passed to
* sg_alloc_table_chained
*
* Description:
* Free an sg table previously allocated and setup with
* sg_alloc_table_chained().
*
* @nents_first_chunk has to be same with that same parameter passed
* to sg_alloc_table_chained().
*
**/
void sg_free_table_chained(struct sg_table *table,
unsigned nents_first_chunk)
{
if (table->orig_nents <= nents_first_chunk)
return;
if (nents_first_chunk == 1)
nents_first_chunk = 0;
__sg_free_table(table, SG_CHUNK_SIZE, nents_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
* @nents_first_chunk: number of the SGL of @first_chunk
*
* Description:
* Allocate and chain SGLs in an sg table. If @nents@ is larger than
* @nents_first_chunk a chained sg table will be setup. @first_chunk is
* ignored if nents_first_chunk <= 1 because user expects the SGL points
* non-chain SGL.
*
**/
int sg_alloc_table_chained(struct sg_table *table, int nents,
struct scatterlist *first_chunk, unsigned nents_first_chunk)
{
int ret;
BUG_ON(!nents);
if (first_chunk && nents_first_chunk) {
if (nents <= nents_first_chunk) {
table->nents = table->orig_nents = nents;
sg_init_table(table->sgl, nents);
return 0;
}
}
/* User supposes that the 1st SGL includes real entry */
if (nents_first_chunk <= 1) {
first_chunk = NULL;
nents_first_chunk = 0;
}
ret = __sg_alloc_table(table, nents, SG_CHUNK_SIZE,
first_chunk, nents_first_chunk,
GFP_ATOMIC, sg_pool_alloc);
if (unlikely(ret))
sg_free_table_chained(table, nents_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;
mempool_destroy(sgp->pool);
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);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...