On Sun, Feb 05, 2017 at 08:04:12AM +0000, Mateusz Guzik wrote: > Author: mjg > Date: Sun Feb 5 08:04:11 2017 > New Revision: 313275 > URL: https://svnweb.freebsd.org/changeset/base/313275 > > Log: > mtx: move lockstat handling out of inline primitives > > Lockstat requires checking if it is enabled and if so, calling a 6 argument > function. Further, determining whether to call it on unlock requires > pre-reading the lock value. > > This is problematic in at least 3 ways: > - more branches in the hot path than necessary > - additional cacheline ping pong under contention > - bigger code > > Instead, check first if lockstat handling is necessary and if so, just fall > back to regular locking routines. For this purpose a new macro is introduced > (LOCKSTAT_PROFILE_ENABLED). > > LOCK_PROFILING uninlines all primitives. Fold in the current inline lock > variant into the _mtx_lock_flags to retain the support. With this change > the inline variants are not used when LOCK_PROFILING is defined and thus > can ignore its existence. > > This results in: > text data bss dec hex filename > 22259667 1303208 4994976 28557851 1b3c21b kernel.orig > 21797315 1303208 4994976 28095499 1acb40b kernel.patched > > i.e. about 3% reduction in text size. > > A remaining action is to remove spurious arguments for internal kernel > consumers.
Do you planed MFC all of this? _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
