(resent to list) Dear Wolfgang Denk,
Am 29.09.2010 um 22:01 schrieb Wolfgang Denk: > Dear =?UTF-8?q?Andreas=20Bie=C3=9Fmann?=, > > In message <[email protected]> > you wrote: [snip] >> * unreasonably large numbers (and thus memory footprint) for >> * big flash environments (>8,000 entries for 64 KB >> * envrionment size), so we clip it to a reasonable value >> * (which can be overwritten in the board config file if >> * needed). >> + * >> + * But in some cases it is necessary to have another algorithm to >> + * get the size of hash table. Especially for extremely small buffers >> + * there is the flag H_ALG_SMALL_BUF which takes another factor to >> + * calculate the hash table size. >> */ >> >> if (!htab->table) { >> - int nent = size / 8; >> + int nent; >> + if (flag & H_ALG_SMALL_BUF) >> + nent = size / 2; >> + else >> + nent = size / 8; > > Did you read the comment above? Yes, I did. > With your configuration, importing a 64 kB environment buffer would > result in 32 k entries in the hash table. Well therefore we have another 'algorithm' implemented to cope with this. The flag H_ALG_SMALL_BUF should be set especially when importing a small buffer. Anyhow the maximum limit some lines below will never be exceeded. > This obviously makes no > sense. > > I think we should rather make sure that a certain minimum of entries > will always be available, for exmaple something like this: > > int nent = 64 + size / 8; This sounds also good but why do not calculate as before and after that check some (maybe definable) borders? How about: int nent = size / 8; if (nent < CONFIG_ENV_MIN_ENTRIES) nent = CONFIG_ENV_MIN_ENTRIES; ... > or similar. > > What do you think? How about my suggestion? > [Actually I think the current setting (size / 8) is _way_ too > conservative in most cases. eventually we'd really be better off with > something like "64 + size / 32" or so. I'm interested in feedback - > the statistics I have about environment settings (number of entries > versus total size) is unfortunately a bit limited, and since most of > the boards come from the same hands they follow a common style, which > eventually is not what other users do.] Well in most cases the environment needs a static size. The actual size of environment has (in my view) no/small connection to space for environment in NV memory. In most cases the space reserved for environment is way to big cause of sector boundaries. Therefore I think it would meet the needs when we have one (configurable) size for hash table without the calculation. regards Andreas Bießmann > Best regards, > > Wolfgang Denk > > -- > DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [email protected] > As far as we know, our computer has never had an undetected error. > -- Weisert _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
