Skip to content

Commit

Permalink
mm/zswap: change per-cpu mutex and buffer to per-acomp_ctx
Browse files Browse the repository at this point in the history 
First of all, we need to rename acomp_ctx->dstmem field to buffer, since
we are now using for purposes other than compression.

Then we change per-cpu mutex and buffer to per-acomp_ctx, since them
belong to the acomp_ctx and are necessary parts when used in the
compress/decompress contexts.

So we can remove the old per-cpu mutex and dstmem.

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Chris Li <chrisl@kernel.org> (Google)
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  • Loading branch information
@akpm00
Chengming Zhou authored and akpm00 committed Dec 29, 2023
1 parent e947ba0 commit 8ba2f84
Show file tree
Hide file tree
Showing 2 changed files with 33 additions and 72 deletions.
1 change: 0 additions & 1 deletion include/linux/cpuhotplug.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -124,7 +124,6 @@ enum cpuhp_state {
CPUHP_ARM_BL_PREPARE,
CPUHP_TRACE_RB_PREPARE,
CPUHP_MM_ZS_PREPARE,
CPUHP_MM_ZSWP_MEM_PREPARE,
CPUHP_MM_ZSWP_POOL_PREPARE,
CPUHP_KVM_PPC_BOOK3S_PREPARE,
CPUHP_ZCOMP_PREPARE,
Expand Down
104 changes: 33 additions & 71 deletions mm/zswap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -161,8 +161,8 @@ struct crypto_acomp_ctx {
struct crypto_acomp *acomp;
struct acomp_req *req;
struct crypto_wait wait;
u8 *dstmem;
struct mutex *mutex;
u8 *buffer;
struct mutex mutex;
};

/*
Expand Down Expand Up @@ -688,72 +688,35 @@ static void zswap_alloc_shrinker(struct zswap_pool *pool)
/*********************************
* per-cpu code
**********************************/
static DEFINE_PER_CPU(u8 *, zswap_dstmem);
/*
* If users dynamically change the zpool type and compressor at runtime, i.e.
* zswap is running, zswap can have more than one zpool on one cpu, but they
* are sharing dtsmem. So we need this mutex to be per-cpu.
*/
static DEFINE_PER_CPU(struct mutex *, zswap_mutex);

static int zswap_dstmem_prepare(unsigned int cpu)
{
struct mutex *mutex;
u8 *dst;

dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
if (!dst)
return -ENOMEM;

mutex = kmalloc_node(sizeof(*mutex), GFP_KERNEL, cpu_to_node(cpu));
if (!mutex) {
kfree(dst);
return -ENOMEM;
}

mutex_init(mutex);
per_cpu(zswap_dstmem, cpu) = dst;
per_cpu(zswap_mutex, cpu) = mutex;
return 0;
}

static int zswap_dstmem_dead(unsigned int cpu)
{
struct mutex *mutex;
u8 *dst;

mutex = per_cpu(zswap_mutex, cpu);
kfree(mutex);
per_cpu(zswap_mutex, cpu) = NULL;

dst = per_cpu(zswap_dstmem, cpu);
kfree(dst);
per_cpu(zswap_dstmem, cpu) = NULL;

return 0;
}

static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
{
struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu);
struct crypto_acomp *acomp;
struct acomp_req *req;
int ret;

mutex_init(&acomp_ctx->mutex);

acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
if (!acomp_ctx->buffer)
return -ENOMEM;

acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu));
if (IS_ERR(acomp)) {
pr_err("could not alloc crypto acomp %s : %ld\n",
pool->tfm_name, PTR_ERR(acomp));
return PTR_ERR(acomp);
ret = PTR_ERR(acomp);
goto acomp_fail;
}
acomp_ctx->acomp = acomp;

req = acomp_request_alloc(acomp_ctx->acomp);
if (!req) {
pr_err("could not alloc crypto acomp_request %s\n",
pool->tfm_name);
crypto_free_acomp(acomp_ctx->acomp);
return -ENOMEM;
ret = -ENOMEM;
goto req_fail;
}
acomp_ctx->req = req;

Expand All @@ -766,10 +729,13 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &acomp_ctx->wait);

acomp_ctx->mutex = per_cpu(zswap_mutex, cpu);
acomp_ctx->dstmem = per_cpu(zswap_dstmem, cpu);

return 0;

req_fail:
crypto_free_acomp(acomp_ctx->acomp);
acomp_fail:
kfree(acomp_ctx->buffer);
return ret;
}

static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
Expand All @@ -782,6 +748,7 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
acomp_request_free(acomp_ctx->req);
if (!IS_ERR_OR_NULL(acomp_ctx->acomp))
crypto_free_acomp(acomp_ctx->acomp);
kfree(acomp_ctx->buffer);
}

return 0;
Expand Down Expand Up @@ -1391,12 +1358,12 @@ static void __zswap_load(struct zswap_entry *entry, struct page *page)
u8 *src;

acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
mutex_lock(acomp_ctx->mutex);
mutex_lock(&acomp_ctx->mutex);

src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
if (!zpool_can_sleep_mapped(zpool)) {
memcpy(acomp_ctx->dstmem, src, entry->length);
src = acomp_ctx->dstmem;
memcpy(acomp_ctx->buffer, src, entry->length);
src = acomp_ctx->buffer;
zpool_unmap_handle(zpool, entry->handle);
}

Expand All @@ -1406,7 +1373,7 @@ static void __zswap_load(struct zswap_entry *entry, struct page *page)
acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, PAGE_SIZE);
BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait));
BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE);
mutex_unlock(acomp_ctx->mutex);
mutex_unlock(&acomp_ctx->mutex);

if (zpool_can_sleep_mapped(zpool))
zpool_unmap_handle(zpool, entry->handle);
Expand Down Expand Up @@ -1622,13 +1589,17 @@ bool zswap_store(struct folio *folio)
/* compress */
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);

mutex_lock(acomp_ctx->mutex);
mutex_lock(&acomp_ctx->mutex);

dst = acomp_ctx->dstmem;
dst = acomp_ctx->buffer;
sg_init_table(&input, 1);
sg_set_page(&input, page, PAGE_SIZE, 0);

/* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */
/*
* We need PAGE_SIZE * 2 here since there maybe over-compression case,
* and hardware-accelerators may won't check the dst buffer size, so
* giving the dst buffer with enough length to avoid buffer overflow.
*/
sg_init_one(&output, dst, PAGE_SIZE * 2);
acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen);
/*
Expand Down Expand Up @@ -1668,7 +1639,7 @@ bool zswap_store(struct folio *folio)
buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO);
memcpy(buf, dst, dlen);
zpool_unmap_handle(zpool, handle);
mutex_unlock(acomp_ctx->mutex);
mutex_unlock(&acomp_ctx->mutex);

/* populate entry */
entry->swpentry = swp_entry(type, offset);
Expand Down Expand Up @@ -1711,7 +1682,7 @@ bool zswap_store(struct folio *folio)
return true;

put_dstmem:
mutex_unlock(acomp_ctx->mutex);
mutex_unlock(&acomp_ctx->mutex);
put_pool:
zswap_pool_put(entry->pool);
freepage:
Expand Down Expand Up @@ -1886,13 +1857,6 @@ static int zswap_setup(void)
goto cache_fail;
}

ret = cpuhp_setup_state(CPUHP_MM_ZSWP_MEM_PREPARE, "mm/zswap:prepare",
zswap_dstmem_prepare, zswap_dstmem_dead);
if (ret) {
pr_err("dstmem alloc failed\n");
goto dstmem_fail;
}

ret = cpuhp_setup_state_multi(CPUHP_MM_ZSWP_POOL_PREPARE,
"mm/zswap_pool:prepare",
zswap_cpu_comp_prepare,
Expand Down Expand Up @@ -1924,8 +1888,6 @@ static int zswap_setup(void)
if (pool)
zswap_pool_destroy(pool);
hp_fail:
cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);
dstmem_fail:
kmem_cache_destroy(zswap_entry_cache);
cache_fail:
/* if built-in, we aren't unloaded on failure; don't allow use */
Expand Down

0 comments on commit 8ba2f84

Please sign in to comment.