On Wed, Jan 13, 2021 at 10:33:01PM -0800, Junio C Hamano wrote: > Taylor Blau <me@xxxxxxxxxxxx> writes: > > > 'estimate_repack_memory()' takes into account the amount of memory > > required to load the reverse index in memory by multiplying the assumed > > number of objects by the size of the 'revindex_entry' struct. > > > > Prepare for hiding the definition of 'struct revindex_entry' by removing > > a 'sizeof()' of that type from outside of pack-revindex.c. Instead, > > guess that one off_t and one uint32_t are required per object. Strictly > > speaking, this is a worse guess than asking for 'sizeof(struct > > revindex_entry)' directly, since the true size of this struct is 16 > > bytes with padding on the end of the struct in order to align the offset > > field. > > Meaning that we under-estimate by 25%? In this area, yes. I'm skeptical that this estimate is all that important, since it doesn't seem to take into account the memory required to select delta/base candidates [1]. Thanks, Taylor [1]: https://lore.kernel.org/git/X%2F1roycRbYPjnI3l@xxxxxxxxxxxxxxxxxxxxxxx/
