Re: [sqlite] Stack allocation upper bound with SQLITE_USE_ALLOCA
On Wed, Apr 3, 2019 at 8:55 AM Richard Hipp wrote: > > On 4/3/19, Jonathan Brandmeyer wrote: > > What is the upper bound for stack consumption under the > > SQLITE_USE_ALLOCA compile-time option? I see that there are a number > > of configurable size limits available as compile-time and/or run-time > > options. Which ones affect the maximum alloca? > > > > I think the maximum alloca() allocation will be 7x the page size for > the database file. So a little less than 0.5 MB assuming a maximum > page size of 64K. Thanks! -- Jonathan Brandmeyer ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Stack allocation upper bound with SQLITE_USE_ALLOCA
Jonathan Brandmeyer wrote: > What is the upper bound for stack consumption under the > SQLITE_USE_ALLOCA compile-time option? I see that there are a number > of configurable size limits available as compile-time and/or run-time > options. Which ones affect the maximum alloca? > > Thanks, > Jonathan Brandmeyer I recall using this tool to measure stack usage on Linux: https://github.com/d99kris/stackusage It gives you the stack high watermarks for each thread, with no noticeable runtime overhead. Of course, there is no guarantee that you hit the theoritical worse case for stack usage while using the tool, but at least you get at least the typical stack usage. You could try measuring with and without -DSQLITE_USE_ALLOCA. Other relevant defines that may influence stack usage: SQLITE_SPELLFIX_STACKALLOC_SZ SQLITE_SMALL_STACK Dominique ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Stack allocation upper bound with SQLITE_USE_ALLOCA
On 4/3/19, Jonathan Brandmeyer wrote: > What is the upper bound for stack consumption under the > SQLITE_USE_ALLOCA compile-time option? I see that there are a number > of configurable size limits available as compile-time and/or run-time > options. Which ones affect the maximum alloca? > I think the maximum alloca() allocation will be 7x the page size for the database file. So a little less than 0.5 MB assuming a maximum page size of 64K. -- D. Richard Hipp d...@sqlite.org ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
