Merge pull request #2864 from terrelln/linux-opt

[linux-kernel] Don't inline function in zstd_opt.c

contrib/linux-kernel/Makefile

@@ -41,7 +41,6 @@ libzstd:
 		-DZSTD_MEMORY_SANITIZER=0 \
 		-DZSTD_DATAFLOW_SANITIZER=0 \
 		-DZSTD_COMPRESS_HEAPMODE=1 \
-		-UZSTD_NO_INLINE \
 		-UNO_PREFETCH \
 		-U__cplusplus \
 		-UZSTD_DLL_EXPORT \
@@ -55,7 +54,8 @@ libzstd:
 		-RZSTD_FALLTHROUGH=fallthrough \
 		-DZSTD_HAVE_WEAK_SYMBOLS=0 \
 		-DZSTD_TRACE=0 \
-		-DZSTD_NO_TRACE
+		-DZSTD_NO_TRACE \
+		-DZSTD_LINUX_KERNEL
 	mv linux/lib/zstd/zstd.h linux/include/linux/zstd_lib.h
 	mv linux/lib/zstd/zstd_errors.h linux/include/linux/
 	cp linux_zstd.h linux/include/linux/zstd.h

contrib/linux-kernel/test/macro-test.sh

@@ -36,7 +36,6 @@ test_not_present "ZSTD_NO_INTRINSICS"
 test_not_present "ZSTD_NO_UNUSED_FUNCTIONS"
 test_not_present "ZSTD_LEGACY_SUPPORT"
 test_not_present "STATIC_BMI2"
-test_not_present "ZSTD_NO_INLINE"
 test_not_present "ZSTD_DLL_EXPORT"
 test_not_present "ZSTD_DLL_IMPORT"
 test_not_present "__ICCARM__"

lib/compress/zstd_opt.c

@@ -8,6 +8,20 @@
  * You may select, at your option, one of the above-listed licenses.
  */
 
+/**
+ * Disable inlining for the optimal parser for the kernel build.
+ * It is unlikely to be used in the kernel, and where it is used
+ * latency shouldn't matter because it is very slow to begin with.
+ * We prefer a ~180KB binary size win over faster optimal parsing.
+ *
+ * TODO(https://github.com/facebook/zstd/issues/2862):
+ * Improve the code size of the optimal parser in general, so we
+ * don't need this hack for the kernel build.
+ */
+#ifdef ZSTD_LINUX_KERNEL
+#define ZSTD_NO_INLINE 1
+#endif
+
 #include "zstd_compress_internal.h"
 #include "hist.h"
 #include "zstd_opt.h"