On 18 Jan 2021, at 21:19, Konstantin Belousov <kostik...@gmail.com> wrote: > On Mon, Jan 18, 2021 at 08:45:43PM +0000, Alexander V. Chernikov wrote: >> 17.01.2021, 17:30, "Konstantin Belousov" <k...@freebsd.org>: >>> The branch main has been updated by kib: >>> >>> URL: >>> https://cgit.FreeBSD.org/src/commit/?id=3b15beb30b3b4ba17bae3d1d43c8c04ff862bb57 >>> >>> commit 3b15beb30b3b4ba17bae3d1d43c8c04ff862bb57 >>> Author: Konstantin Belousov <k...@freebsd.org> >>> AuthorDate: 2021-01-14 03:59:34 +0000 >>> Commit: Konstantin Belousov <k...@freebsd.org> >>> CommitDate: 2021-01-17 17:29:05 +0000 >>> >>> Implement malloc_domainset_aligned(9). >> Hi Kostik, >> >> This change makes my vm panic in usb code. No dump, as dumpdev not mounted >> yet. >> >> Note: the below lines have been OCR'ed, so there may be some errors. >> >> Root mount waiting for: CAM usbus0 usbus1 >> panic: malloc_domainset_aligned: result not aligned 0xfffff8000551ca80 size >> 0x180 align 0x100 > > Try this. > > ... > if (size < align) > - size = align; > - res = malloc_domainset(size, mtp, ds, flags); > + asize = align; > + else if (!powerof2(size)) > + asize = roundup2(size, align); > + else > + asize = size;
Why not just `asize = roundup2(size, align)`? It's only 3 instructions (4 on Clang due to a missed combine) on amd64 and I'd be very surprised if the branching version were faster even in the fast path case. Plus it's much easier to read; currently it looks like there's something unusual going on but there really isn't. https://godbolt.org/z/rv6qs7 FWIW Jess _______________________________________________ dev-commits-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-all To unsubscribe, send any mail to "dev-commits-src-all-unsubscr...@freebsd.org"
