On Monday, August 03, 2015 11:31:58 AM Steven Hartland wrote: > On 03/08/2015 10:47, Slawa Olhovchenkov wrote: > > On Mon, Aug 03, 2015 at 09:34:10AM +0000, Steven Hartland wrote: > >> Author: smh > >> Date: Mon Aug 3 09:34:09 2015 > >> New Revision: 286223 > >> URL: https://svnweb.freebsd.org/changeset/base/286223 > >> > >> Log: > >> Fix KSTACK_PAGES check in ZFS module > >> > >> The check introduced by r285946 failed to add the dependency on > >> opt_kstack_pages.h which meant the default value for the platform > >> instead > >> of the customised options KSTACK_PAGES=X was being tested. > >> > >> Also wrap in #ifdef __FreeBSD__ for portability. > > > > /usr/src/sys/kern/kern_proc.c:int kstack_pages = KSTACK_PAGES; > > > > May be check variable kstack_pages is best way? > > Eliminate dependency on foreign opt_XXXX. > > I did think of that but as other modules such as dtrace, which is also > cddl code, already have this dependency I went with this. > > I'm easy though, if there's a concusses that kstack_pages or possibly > curthread->td_kstack_pages, which would take into account the > possibility of varied thread stack sizes, then I can make that change. > > What do others think?
The whole thing has missing the point.
Changing the default for the entire kernel just because the zfs compat
wrappers can't be bothered requesting a suitable value is.. unfortunate..
particularly when it is in freebsd-provided code, not upstream zfs code.
Fix the kproc_kthread_add() calls in do_thread_create() and zvol_geom_run()
instead. Enforce a lower bound there for zfs threads instead of making the
entire rest of the kernel use more memory.
eg: I'm thinking along these lines:
Index: cddl/compat/opensolaris/sys/proc.h
====================================================
--- cddl/compat/opensolaris/sys/proc.h (revision 286224)
+++ cddl/compat/opensolaris/sys/proc.h (working copy)
@@ -77,6 +77,8 @@
ASSERT(state == TS_RUN);
ASSERT(pp == &p0);
+ if (stksize < 16384)
+ stksize = 16384; /* Enforce lower bound on ZFS threads */
error = kproc_kthread_add(proc, arg, &zfsproc, &td, RFSTOPPED,
stksize / PAGE_SIZE, "zfskern", "solthread %p", proc);
if (error == 0) {
Beware, some platforms have large pages (eg: ia64 in -stable has 8k, 16k or
32k pages, from memory). Specifying an arbitrary number of pages in code
that's supposed to be portable isn't a good idea.
--
Peter Wemm - pe...@wemm.org; pe...@freebsd.org; pe...@yahoo-inc.com; KI6FJV
UTF-8: for when a ' or ... just won\342\200\231t do\342\200\246
signature.asc
Description: This is a digitally signed message part.
