zswap_compress_folio() is modified to detect if the pool's acomp_ctx has
more than one "nr_reqs", which will be the case if the cpu onlining code
has allocated batching resources in the acomp_ctx based on the queries to
acomp_has_async_batching() and crypto_acomp_batch_size(). If multiple
"nr_reqs" are available in the acomp_ctx, it means compress batching can be
used with a batch-size of "acomp_ctx->nr_reqs".
If compress batching can be used with the given zswap pool,
zswap_compress_folio() will invoke the newly added zswap_batch_compress()
procedure to compress and store the folio in batches of
"acomp_ctx->nr_reqs" pages. The batch size is effectively
"acomp_ctx->nr_reqs".
zswap_batch_compress() calls crypto_acomp_batch_compress() to compress each
batch of (up to) "acomp_ctx->nr_reqs" pages. The iaa_crypto driver
will compress each batch of pages in parallel in the Intel IAA hardware
with 'async' mode and request chaining.
Hence, zswap_batch_compress() does the same computes for a batch, as
zswap_compress() does for a page; and returns true if the batch was
successfully compressed/stored, and false otherwise.
If the pool does not support compress batching, zswap_compress_folio()
calls zswap_compress() for each individual page in the folio, as before.
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
---
mm/zswap.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 105 insertions(+), 4 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index 1be0f1807bfc..f336fafe24c4 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1467,17 +1467,118 @@ static void shrink_worker(struct work_struct *w)
* main API
**********************************/
+static bool zswap_batch_compress(struct folio *folio,
+ long index,
+ unsigned int batch_size,
+ struct zswap_entry *entries[],
+ struct zswap_pool *pool,
+ struct crypto_acomp_ctx *acomp_ctx)
+{
+ int comp_errors[ZSWAP_MAX_BATCH_SIZE] = { 0 };
+ unsigned int dlens[ZSWAP_MAX_BATCH_SIZE];
+ struct page *pages[ZSWAP_MAX_BATCH_SIZE];
+ unsigned int i, nr_batch_pages;
+ bool ret = true;
+
+ nr_batch_pages = min((unsigned int)(folio_nr_pages(folio) - index), batch_size);
+
+ for (i = 0; i < nr_batch_pages; ++i) {
+ pages[i] = folio_page(folio, index + i);
+ dlens[i] = PAGE_SIZE;
+ }
+
+ mutex_lock(&acomp_ctx->mutex);
+
+ /*
+ * Batch compress @nr_batch_pages. If IAA is the compressor, the
+ * hardware will compress @nr_batch_pages in parallel.
+ */
+ ret = crypto_acomp_batch_compress(
+ acomp_ctx->reqs,
+ &acomp_ctx->wait,
+ pages,
+ acomp_ctx->buffers,
+ dlens,
+ comp_errors,
+ nr_batch_pages);
+
+ if (ret) {
+ /*
+ * All batch pages were successfully compressed.
+ * Store the pages in zpool.
+ */
+ struct zpool *zpool = pool->zpool;
+ gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
+
+ if (zpool_malloc_support_movable(zpool))
+ gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
+
+ for (i = 0; i < nr_batch_pages; ++i) {
+ unsigned long handle;
+ char *buf;
+ int err;
+
+ err = zpool_malloc(zpool, dlens[i], gfp, &handle);
+
+ if (err) {
+ if (err == -ENOSPC)
+ zswap_reject_compress_poor++;
+ else
+ zswap_reject_alloc_fail++;
+
+ ret = false;
+ break;
+ }
+
+ buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO);
+ memcpy(buf, acomp_ctx->buffers[i], dlens[i]);
+ zpool_unmap_handle(zpool, handle);
+
+ entries[i]->handle = handle;
+ entries[i]->length = dlens[i];
+ }
+ } else {
+ /* Some batch pages had compression errors. */
+ for (i = 0; i < nr_batch_pages; ++i) {
+ if (comp_errors[i]) {
+ if (comp_errors[i] == -ENOSPC)
+ zswap_reject_compress_poor++;
+ else
+ zswap_reject_compress_fail++;
+ }
+ }
+ }
+
+ mutex_unlock(&acomp_ctx->mutex);
+
+ return ret;
+}
+
static bool zswap_compress_folio(struct folio *folio,
struct zswap_entry *entries[],
struct zswap_pool *pool)
{
long index, nr_pages = folio_nr_pages(folio);
+ struct crypto_acomp_ctx *acomp_ctx;
+ unsigned int batch_size;
- for (index = 0; index < nr_pages; ++index) {
- struct page *page = folio_page(folio, index);
+ acomp_ctx = raw_cpu_ptr(pool->acomp_ctx);
+ batch_size = acomp_ctx->nr_reqs;
- if (!zswap_compress(page, entries[index], pool))
- return false;
+ if ((batch_size > 1) && (nr_pages > 1)) {
+ for (index = 0; index < nr_pages; index += batch_size) {
+
+ if (!zswap_batch_compress(folio, index, batch_size,
+ &entries[index], pool, acomp_ctx))
+ return false;
+ }
+ } else {
+ for (index = 0; index < nr_pages; ++index) {
+ struct page *page = folio_page(folio, index);
+
+ if (!zswap_compress(page, entries[index], pool))
+ return false;
+ }
}
return true;
--
2.27.0
