Messages in this thread | | | Date | Mon, 24 Nov 2014 09:38:20 +0100 | Subject | Re: [PATCH 0/6] kernel tinification: optionally compile out splice family of syscalls (splice, vmsplice, tee and sendfile) | From | Geert Uytterhoeven <> |
| |
On Mon, Nov 24, 2014 at 12:36 AM, Josh Triplett <josh@joshtriplett.org> wrote: > On Sun, Nov 23, 2014 at 09:30:40PM +0100, Pieter Smith wrote: >> On Sun, Nov 23, 2014 at 11:43:26AM -0800, Josh Triplett wrote: >> > On Sun, Nov 23, 2014 at 01:46:23PM -0500, David Miller wrote: >> > > Truly removing sendfile/sendpage means that you can't even compile NFS >> > > into the tree. >> > >> > If you mean the in-kernel nfsd (CONFIG_NFSD), that already has a large >> > stack of "select" and "depends on", both directly and indirectly; adding >> > a "select SPLICE_SYSCALL" to it seems fine. (That select does need >> > adding, though. Pieter, you need to test-compile more than just >> > tinyconfig and defconfig. Try an allyesconfig with *just* splice turned >> > off, and make sure that compiles.) >> >> Did exacly that. Took forever on my hardware, but no problems. > > Ah, I see. Looking more closely at nfsd, it looks like it already has a > code path for filesystems that don't do splice. I think, rather than > making nfsd select SPLICE_SYSCALL, that it would suffice to change the > "rqstp->rq_splice_ok = true;" in svc_process_common (net/sunrpc/svc.c) > to: > > rqstp->rq_splice_ok = IS_ENABLED(CONFIG_SPLICE_SYSCALL); > > Then nfsd should simply *always* fall back to its non-splice support.
Hence I suggest adding to the nfsd help text:
While nfsd works without SPLICE_SYSCALL, you may want to enable SPLICE_SYSCALL for <...> (performance?) reasons.
(Hmm, does Kconfig need a "suggests", cfr. Debian package dependencies?)
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
| |