path: root/doc
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authorTomasz Jozwiak <>2019-02-15 10:44:32 +0100
committerAkhil Goyal <>2019-03-22 14:27:46 +0100
commita720e6740afcd6d21955d188c6e6a7136fcc7d6c (patch)
treec6bb26487e2f3d07811dc87f2732c622a26686e6 /doc
parentfff7b0ddce74ce4e8e1185763fec0f7b72b34ecd (diff)
compress/qat: add fallback to fixed compression
This patch adds fallback to fixed compression feature during dynamic compression, when the input data size is greater than IM buffer size / 1.1. This feature doesn't stop compression proccess when IM buffer can be too small to handle produced data. Signed-off-by: Tomasz Jozwiak <> Acked-by: Fiona Trahe <>
Diffstat (limited to 'doc')
1 files changed, 5 insertions, 5 deletions
diff --git a/doc/guides/cryptodevs/qat.rst b/doc/guides/cryptodevs/qat.rst
index b7eace1..beb6760 100644
--- a/doc/guides/cryptodevs/qat.rst
+++ b/doc/guides/cryptodevs/qat.rst
@@ -188,11 +188,11 @@ allocated while for GEN1 devices, 12 buffers are allocated, plus 1472 bytes over
If the compressed output of a Deflate operation using Dynamic Huffman
Encoding is too big to fit in an intermediate buffer, then the
- operation will return RTE_COMP_OP_STATUS_ERROR and an error will be
- displayed. Options for the application in this case
- are to split the input data into smaller chunks and resubmit
- in multiple operations or to configure QAT with
- larger intermediate buffers.
+ operation will fall back to fixed compression rather than failing the operation.
+ To avoid this less performant case, applications should configure
+ the intermediate buffer size to be larger than the expected input data size
+ (compressed output size is usually unknown, so the only option is to make
+ larger than the input size).
Device and driver naming