On (20/02/13 14:07), Petr Mladek wrote: > On Wed 2020-02-05 17:12:12, John Ogness wrote: > > On 2020-02-05, lijiang <lijiang@xxxxxxxxxx> wrote: > > > Do you have any suggestions about the size of CONFIG_LOG_* and > > > CONFIG_PRINTK_* options by default? > > > > The new printk implementation consumes more than double the memory that > > the current printk implementation requires. This is because dictionaries > > and meta-data are now stored separately. > > > > If the old defaults (LOG_BUF_SHIFT=17 LOG_CPU_MAX_BUF_SHIFT=12) were > > chosen because they are maximally acceptable defaults, then the defaults > > should be reduced by 1 so that the final size is "similar" to the > > current implementation. > > > > If instead the defaults are left as-is, a machine with less than 64 CPUs > > will reserve 336KiB for printk information (128KiB text, 128KiB > > dictionary, 80KiB meta-data). > > > > It might also be desirable to reduce the dictionary size (maybe 1/4 the > > size of text?). > > Good questions. It would be great to check the usage on some real > systems. [..] > I wish the dictionaries were never added ;-) They complicate the code > and nobody knows how many people actually use the information. Maybe we can have CONFIG_PRINTK_EXTRA_PAYLOAD [for dicts] so people can compile it out if it's not needed. This can save several bytes here and there. -ss _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
