> From: Seth Jennings [mailto:sjenning@xxxxxxxxxxxxxxxxxx] > Subject: [PATCHv6 4/8] zswap: add to mm/ > > +/* > + * Maximum compression ratio, as as percentage, for an acceptable > + * compressed page. Any pages that do not compress by at least > + * this ratio will be rejected. > +*/ > +static unsigned int zswap_max_compression_ratio = 80; > +module_param_named(max_compression_ratio, > + zswap_max_compression_ratio, uint, 0644); Unless this is a complete coincidence, I believe that the default value "80" is actually: (100 * (1L >> ZS_MAX_ZSPAGE_ORDER)) / ((1L >> ZS_MAX_ZSPAGE_ORDER)) + 1) (though the constant ZS_MAX_ZSPAGE_ORDER is not currently defined outside of zsmalloc.c) because pages that compress less efficiently than this always require a full pageframe in zsmalloc. True? If this change were made, is there any real reason for this to be a user-selectable parameter, i.e. given the compression internals knowledge necessary to understand what value should be selected, would any mortal sysadmin ever want to change it or know what would be a reasonable value to change it to? _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
