Re: [osol-discuss] kernel threads
> On Mon, 28 Jan 2008, [EMAIL PROTECTED] wrote: > > [ ... ] > >> My present code uses thread_create(). I am seeing > kernel panics due to an ASSERT fail in the > sfmmu_tsbmiss_exception(). > > Can you please post the part of the output of > "::msgbuf" (from > mdb on your crashdump) following the "panic[cpu...] " > line ? > panic[cpu0]/thread=2a108169cc0: BAD TRAP: type=31 rp=2a1081693a0 addr=349 mmu_fsr=0 occurred in module "unix" du e to a NULL pointer dereference updisk: trap type = 0x31 addr=0x349 pid=984, pc=0x1034db8, sp=0x2a108168c41, tstate=0x441601, context=0x1 g1-g7: 60016022090, 2a108169cc0, 42f90, 8, 121c574, 0, 2a108169cc0 02a1081690c0 unix:die+78 (31, 2a1081693a0, 349, 0, 2a108169180, 108dc00) %l0-3: 0031 0100 2000 %l4-7: 0182d0f0 0182d000 0005 0001 02a1081691a0 unix:trap+9d8 (2a1081693a0, 0, 5, 1c00, 0, 1) %l0-3: 060016022090 0031 %l4-7: e000 004325ca 0005 0001 02a1081692f0 unix:ktl0+64 (60008b5cb64, 42f98, 1, fff8, 7331b, 1 ) %l0-3: 0180c000 00441601 0101e3a8 %l4-7: 0300014c3e40 004325ca 02a1081693a0 02a108169440 genunix:uiomove+90 (2a1081695a0, 42001, 31, 0, 43254b, 60015481 0c8) %l0-3: 0180c000 0001 1c00 %l4-7: 0300014c3e40 004325ca 0002 0180c000 02a1081694f0 unix:ktl0+64 (60008b5cb64, 42f98, 1, fff8, 7331b, 1 ) %l0-3: 0180c000 80001607 01034d64 %l4-7: 0008 02a108169940 02a1081695a0 02a108169640 genunix:uiomove+90 (60008b5cb5c, 8, 0, 2a108169950, 0, 8) %l0-3: 02a108169960 02a108169950 0002 8000 %l4-7: 0008 02a108169940 02a108169950 060008b5cb64 02a1081696f0 genunix:struiocopyout+38 (60003b53080, 2a108169950, 2a108169864 , 0, 60008b5cb64, 1) %l0-3: 030015d9bd18 030015d9bc98 0002 8000 %l4-7: 0008 0008 02a108169950 060008b5cb64 02a1081697a0 genunix:strread+4b4 (0, 2a108169950, 0, 30017460860, 0, 0) %l0-3: 030015d9bd18 030015d9bc98 0002 8000 %l4-7: 060003b53080 02a108169870 ipfs:ipfs_in+1e8 (0, 3001bba0940, 30017460860, 8, 2a108169ab0, 0) %l0-3: 018ec400 030015d9bc98 060005e8 %l4-7: 060005e80068 0008 0600153ad4e0 02a108169990 ipfs:ipfs_active_in+ec (60005e8, 3001bba0940, 60016dc0400, 600153a, 0, 60005e800d8) %l0-3: 0600153ad120 704a5400 %l4-7: 060005e80068 060005e8 0600153ad4e0 > I do think you're running way down the wrong track > there. You get a trap > because of an invalid pointer, that the trap handling > mechanism doesn't > tell you that clearly but fails somewhere else is > more than likely just an > artifact. The _real_ meat is elsewhere. > > when you do crashdump analysis, don't always focus > only on the topmost > function in a stacktrace. There's more to it than > that and the bug you try > to track down & fix isn't necessarily at the very > place where things fall > over. > > Are you willing to share that crashdump with the > community ? > I dont think you would like this, Its from Solaris 10 not OpenSolaris. > Thx, > FrankH. > ___ > opensolaris-discuss mailing list > opensolaris-discuss@opensolaris.org This message posted from opensolaris.org ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
Re: [osol-discuss] kernel threads
> On Mon, 28 Jan 2008, [EMAIL PROTECTED] wrote: > > > Hi, > [ ... ] > >>> Calling lwp_create from a kernel driver will get > you > >>> into trouble. Why > >>> would you want to create an LWP from within a > kernel > >>> driver ? > >>> > >>> > >> My present code uses thread_create(). I am seeing > kernel panics due to an ASSERT fail in the > sfmmu_tsbmiss_exception(). > > And why do you think that would have anything to do > with each other ? > > >> > >>> If you're looking for something entirely > different, > >>> the way how to find > >>> out which LWP is executing your kernel driver > code, > >>> use: > >>> > >>> klwp_t *curlwp = ttolwp(threadp()); > >>> Can you clarify what you want to achieve ? > >>> > >>> > >> If I do this in my thread, I am getting curlwp as > NULL. because there is no LWP created when I do a > thread_create(). And this sfmmu_tsbmiss_exception() > is doing the same thing. > >> > >>11824 /* > >>11825* Must set lwp state to LWP_SYS before > >>11826* trying to acquire any adaptive lock > >>11827*/ > > Can you explain that sourcecode comment ? It's wrong, > but why you think > this should be so might give more insight as to what > your expectations > actually are ? > This comment is from /usr/src/uts/sfmmu/vm/hat_sfmmu.c . My intention is just to create a thread and I achieved it by thread_create() but because of this code in sfmmu_tsbmiss_exception() function my code with thread_create() is causing kernel panics. So wondering if I can get rid of this if I can get a valid lwp value. > >>11828 lwp = ttolwp(curthread); > >>11829 ASSERT(lwp); // this is causing kernel > panic > > And what is unusual by that ? Not every thread has an > LWP, it's pretty > normal to see ttolwp(curthread) being NULL. The only > thing that tells you > is that the currently running thread is not part of > any userland process > but has been created by the kernel itself, or by some > kernel driver. > > >> So, to avoid this I was just trying to see if it > is possible to use lwp_create(). > >> > > Creating a kernel thread does not imply that a > klwp_t is created. What > > information from an lwp > > do you need? If there is no user level, you > should not need an lwp. > > So, why do you think > > you need one? > > Seconding Max here - why do you think you need one ? > > Thx, > FrankH. > ___ > opensolaris-discuss mailing list > opensolaris-discuss@opensolaris.org This message posted from opensolaris.org ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
Re: [osol-discuss] kernel threads
> > > On Fri, 25 Jan 2008, ramana polamarasetti wrote: > > > Hi, > > Can anyone tell me what are all the differences > between the threads created with thread_create() and > those created with lwp_create()? > > And is there any way to get an lwp, but using > thread_create()? > > > > Thanks for any help, > > Ramana > > Where do you want to create threads ? In you > application ? In a kernel > driver of yours ? In my kernel module. > > If the former, i.e. you want to use threads in your > application, then > you're way along the wrong path, check thr_create() > resp. pthread_create() > instead. > > If the latter, i.e. you want to create a thread from > within your kernel > driver, then please consider first whether other > asynchronous mechanisms > (taskq or timeout) would do instead. The use of > threads breaks power > management interfaces, and creates > difficult-to-deal-with races on driver > unloading. In any case, if you have to it's > thread_create(). > > Calling lwp_create from a kernel driver will get you > into trouble. Why > would you want to create an LWP from within a kernel > driver ? > My present code uses thread_create(). I am seeing kernel panics due to an ASSERT fail in the sfmmu_tsbmiss_exception(). > > If you're looking for something entirely different, > the way how to find > out which LWP is executing your kernel driver code, > use: > > klwp_t *curlwp = ttolwp(threadp()); > Can you clarify what you want to achieve ? > If I do this in my thread, I am getting curlwp as NULL. because there is no LWP created when I do a thread_create(). And this sfmmu_tsbmiss_exception() is doing the same thing. 11824/* 11825 * Must set lwp state to LWP_SYS before 11826 * trying to acquire any adaptive lock 11827 */ 11828lwp = ttolwp(curthread); 11829ASSERT(lwp); // this is causing kernel panic So, to avoid this I was just trying to see if it is possible to use lwp_create(). > > thanks, > FrankH. > ___ > opensolaris-discuss mailing list > opensolaris-discuss@opensolaris.org Thanks for the reply. This message posted from opensolaris.org ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
[osol-discuss] kernel threads
Hi, Can anyone tell me what are all the differences between the threads created with thread_create() and those created with lwp_create()? And is there any way to get an lwp, but using thread_create()? Thanks for any help, Ramana This message posted from opensolaris.org ___ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
