In the !zpool_can_sleep_mapped() case such as zsmalloc, we need to first
copy the entry->handle memory to a temporary memory, which is allocated
using kmalloc.
Obviously we can reuse the per-compressor dstmem to avoid allocating
every time, since it's percpu-compressor and protected in mutex.
Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
---
mm/zswap.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index a6b4859a0164..d93a7b58b5af 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1758,9 +1758,9 @@ bool zswap_load(struct folio *folio)
struct zswap_entry *entry;
struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
- u8 *src, *dst, *tmp;
+ unsigned int dlen = PAGE_SIZE;
+ u8 *src, *dst;
struct zpool *zpool;
- unsigned int dlen;
bool ret;
VM_WARN_ON_ONCE(!folio_test_locked(folio));
@@ -1782,27 +1782,18 @@ bool zswap_load(struct folio *folio)
goto stats;
}
- zpool = zswap_find_zpool(entry);
- if (!zpool_can_sleep_mapped(zpool)) {
- tmp = kmalloc(entry->length, GFP_KERNEL);
- if (!tmp) {
- ret = false;
- goto freeentry;
- }
- }
-
/* decompress */
- dlen = PAGE_SIZE;
- src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
+ acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
+ mutex_lock(acomp_ctx->mutex);
+ zpool = zswap_find_zpool(entry);
+ src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
if (!zpool_can_sleep_mapped(zpool)) {
- memcpy(tmp, src, entry->length);
- src = tmp;
+ memcpy(acomp_ctx->dstmem, src, entry->length);
+ src = acomp_ctx->dstmem;
zpool_unmap_handle(zpool, entry->handle);
}
- acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
- mutex_lock(acomp_ctx->mutex);
sg_init_one(&input, src, entry->length);
sg_init_table(&output, 1);
sg_set_page(&output, page, PAGE_SIZE, 0);
@@ -1813,15 +1804,13 @@ bool zswap_load(struct folio *folio)
if (zpool_can_sleep_mapped(zpool))
zpool_unmap_handle(zpool, entry->handle);
- else
- kfree(tmp);
ret = true;
stats:
count_vm_event(ZSWPIN);
if (entry->objcg)
count_objcg_event(entry->objcg, ZSWPIN);
-freeentry:
+
spin_lock(&tree->lock);
if (ret && zswap_exclusive_loads_enabled) {
zswap_invalidate_entry(tree, entry);
--
b4 0.10.1
