36  * The algorithms are ran in a collected sample of the input (uncompressed) data.
37  * The sample is formed of 2K reads in PAGE_SIZE intervals, with a maximum size of 4M.
39  * Parsing the sample goes from "low-hanging fruits" (fastest algorithms, likely compressible)
49  * @bkt:	Bytes counts of the sample.
50  * @slen:	Size of the sample.
87  * @bkt:	Byte counts of the sample.
88  * @slen:	Size of the sample.
139 static bool has_repeated_data(const u8 *sample, size_t len)  in has_repeated_data()  argument
143 	return (!memcmp(&sample[0], &sample[s], s));  in has_repeated_data()
162 static int collect_sample(const struct iov_iter *iter, ssize_t max, u8 *sample)  in collect_sample()  argument
192 				memcpy(&sample[s], p, len2);  in collect_sample()
228 	u8 *sample;  in is_compressible()  local
240 	sample = kvzalloc(len, GFP_KERNEL);  in is_compressible()
241 	if (!sample) {  in is_compressible()
247 	/* Sample 2K bytes per page of the uncompressed data. */  in is_compressible()
248 	i = collect_sample(data, len, sample);  in is_compressible()
258 	if (has_repeated_data(sample, len))  in is_compressible()
270 		bkt[sample[i]].count++;  in is_compressible()
287 	kvfree(sample);  in is_compressible()