On Tue, 4 Nov 2014 12:40:41 +0100 Mateusz Guzik <mjgu...@gmail.com> wrote:
> On Tue, Nov 04, 2014 at 11:29:49AM +0000, Hans Petter Selasky wrote: > > Author: hselasky > > Date: Tue Nov 4 11:29:49 2014 > > New Revision: 274088 > > URL: https://svnweb.freebsd.org/changeset/base/274088 > > > > Log: > > Simplify logic a bit. Ensure data buffer is properly aligned, > > especially for platforms where unaligned access is not allowed. > > Make it possible to override the small buffer size. > > > > A simple continuous read string test using libusb showed a > > reduction in CPU usage from roughly 10% to less than 1% using a > > dual-core GHz CPU, when the malloc() operation was skipped for > > small buffers. > > MFC after: 2 weeks > > > > Modified: > > head/sys/kern/sys_generic.c > > > > Modified: head/sys/kern/sys_generic.c > > ============================================================================== > > --- head/sys/kern/sys_generic.c Tue Nov 4 10:25:52 > > 2014 (r274087) +++ head/sys/kern/sys_generic.c Tue > > Nov 4 11:29:49 2014 (r274088) @@ -646,10 +646,13 @@ struct > > ioctl_args { int > > sys_ioctl(struct thread *td, struct ioctl_args *uap) > > { > > +#ifndef SYS_IOCTL_SMALL_SIZE > > +#define SYS_IOCTL_SMALL_SIZE 128 > > +#endif > > + u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(8); > > Should not you align to word size instead? On ARM it needs to be at least 8-byte aligned as this is the largest alignment of any types. Andrew _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
