On Wed, Mar 04, 2020 at 01:15:59PM -0800, Eric Joyner wrote: > Hi Mark, > > Is the addition of #include <sys/_bitcount.h> in sys/sys/refcount.h > actually necessary? I don't see anything in there used in refcount.h, and > the kernel appears to compile without it, at least on amd64.
No, it is left over from an earlier iteration of the patch. I will remove it. Thanks. > On Fri, Feb 28, 2020 at 8:05 AM Mark Johnston <ma...@freebsd.org> wrote: > > > Author: markj > > Date: Fri Feb 28 16:05:18 2020 > > New Revision: 358432 > > URL: https://svnweb.freebsd.org/changeset/base/358432 > > > > Log: > > Add a blocking counter KPI. > > > > refcount(9) was recently extended to support waiting on a refcount to > > drop to zero, as this was needed for a lockless VM object > > paging-in-progress counter. However, this adds overhead to all uses of > > refcount(9) and doesn't really match traditional refcounting semantics: > > once a counter has dropped to zero, the protected object may be freed at > > any point and it is not safe to dereference the counter. > > > > This change removes that extension and instead adds a new set of KPIs, > > blockcount_*, for use by VM object PIP and busy. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
