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mm: zswap: function ordering: compress & decompress functions 

Writeback needs to decompress. Move the (de)compression API above what
will be the consolidated shrinking/writeback code.

Link: https://lkml.kernel.org/r/20240130014208.565554-18-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2024-01-29 20:36:53 -05:00 committed by Andrew Morton
parent 36034bf6fc
commit f91e81d31c
1 changed files with 105 additions and 102 deletions
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207
mm/zswap.c
View File

@ -992,6 +992,111 @@ static void zswap_invalidate_entry(struct zswap_tree *tree,
zswap_entry_put(entry);
}
/*********************************
* compressed storage functions
**********************************/
static bool zswap_compress(struct folio *folio, struct zswap_entry *entry)
{
struct crypto_acomp_ctx *acomp_ctx;
struct scatterlist input, output;
unsigned int dlen = PAGE_SIZE;
unsigned long handle;
struct zpool *zpool;
char *buf;
gfp_t gfp;
int ret;
u8 *dst;
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
mutex_lock(&acomp_ctx->mutex);
dst = acomp_ctx->buffer;
sg_init_table(&input, 1);
sg_set_page(&input, &folio->page, PAGE_SIZE, 0);
/*
* 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);
/*
* it maybe looks a little bit silly that we send an asynchronous request,
* then wait for its completion synchronously. This makes the process look
* synchronous in fact.
* Theoretically, acomp supports users send multiple acomp requests in one
* acomp instance, then get those requests done simultaneously. but in this
* case, zswap actually does store and load page by page, there is no
* existing method to send the second page before the first page is done
* in one thread doing zwap.
* but in different threads running on different cpu, we have different
* acomp instance, so multiple threads can do (de)compression in parallel.
*/
ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait);
dlen = acomp_ctx->req->dlen;
if (ret) {
zswap_reject_compress_fail++;
goto unlock;
}
zpool = zswap_find_zpool(entry);
gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
if (zpool_malloc_support_movable(zpool))
gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
ret = zpool_malloc(zpool, dlen, gfp, &handle);
if (ret == -ENOSPC) {
zswap_reject_compress_poor++;
goto unlock;
}
if (ret) {
zswap_reject_alloc_fail++;
goto unlock;
}
buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO);
memcpy(buf, dst, dlen);
zpool_unmap_handle(zpool, handle);
entry->handle = handle;
entry->length = dlen;
unlock:
mutex_unlock(&acomp_ctx->mutex);
return ret == 0;
}
static void zswap_decompress(struct zswap_entry *entry, struct page *page)
{
struct zpool *zpool = zswap_find_zpool(entry);
struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
u8 *src;
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
mutex_lock(&acomp_ctx->mutex);
src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
if (!zpool_can_sleep_mapped(zpool)) {
memcpy(acomp_ctx->buffer, src, entry->length);
src = acomp_ctx->buffer;
zpool_unmap_handle(zpool, entry->handle);
}
sg_init_one(&input, src, entry->length);
sg_init_table(&output, 1);
sg_set_page(&output, page, PAGE_SIZE, 0);
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);
if (zpool_can_sleep_mapped(zpool))
zpool_unmap_handle(zpool, entry->handle);
}
/*********************************
* shrinker functions
**********************************/
@ -1317,108 +1422,6 @@ resched:
zswap_pool_put(pool);
}
static bool zswap_compress(struct folio *folio, struct zswap_entry *entry)
{
struct crypto_acomp_ctx *acomp_ctx;
struct scatterlist input, output;
unsigned int dlen = PAGE_SIZE;
unsigned long handle;
struct zpool *zpool;
char *buf;
gfp_t gfp;
int ret;
u8 *dst;
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
mutex_lock(&acomp_ctx->mutex);
dst = acomp_ctx->buffer;
sg_init_table(&input, 1);
sg_set_page(&input, &folio->page, PAGE_SIZE, 0);
/*
* 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);
/*
* it maybe looks a little bit silly that we send an asynchronous request,
* then wait for its completion synchronously. This makes the process look
* synchronous in fact.
* Theoretically, acomp supports users send multiple acomp requests in one
* acomp instance, then get those requests done simultaneously. but in this
* case, zswap actually does store and load page by page, there is no
* existing method to send the second page before the first page is done
* in one thread doing zwap.
* but in different threads running on different cpu, we have different
* acomp instance, so multiple threads can do (de)compression in parallel.
*/
ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait);
dlen = acomp_ctx->req->dlen;
if (ret) {
zswap_reject_compress_fail++;
goto unlock;
}
zpool = zswap_find_zpool(entry);
gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
if (zpool_malloc_support_movable(zpool))
gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
ret = zpool_malloc(zpool, dlen, gfp, &handle);
if (ret == -ENOSPC) {
zswap_reject_compress_poor++;
goto unlock;
}
if (ret) {
zswap_reject_alloc_fail++;
goto unlock;
}
buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO);
memcpy(buf, dst, dlen);
zpool_unmap_handle(zpool, handle);
entry->handle = handle;
entry->length = dlen;
unlock:
mutex_unlock(&acomp_ctx->mutex);
return ret == 0;
}
static void zswap_decompress(struct zswap_entry *entry, struct page *page)
{
struct zpool *zpool = zswap_find_zpool(entry);
struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
u8 *src;
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
mutex_lock(&acomp_ctx->mutex);
src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
if (!zpool_can_sleep_mapped(zpool)) {
memcpy(acomp_ctx->buffer, src, entry->length);
src = acomp_ctx->buffer;
zpool_unmap_handle(zpool, entry->handle);
}
sg_init_one(&input, src, entry->length);
sg_init_table(&output, 1);
sg_set_page(&output, page, PAGE_SIZE, 0);
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);
if (zpool_can_sleep_mapped(zpool))
zpool_unmap_handle(zpool, entry->handle);
}
/*********************************
* writeback code
**********************************/