* [PATCH powerpc] init nvram_pstore_info's buf_lock @ 2014-11-17 2:52 Li Zhong 2014-11-18 4:33 ` [powerpc] " Michael Ellerman 0 siblings, 1 reply; 3+ messages in thread From: Li Zhong @ 2014-11-17 2:52 UTC (permalink / raw) To: PowerPC email list; +Cc: Michael Ellerman, Paul Mackerras It seems nvram_pstore_info's buf_lock is not initialized before registering, which causes some strange behavior when trying to obtain the lock during kdump process. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/nvram.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index 11a3b61..054a0ed 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -715,6 +715,8 @@ static int nvram_pstore_init(void) nvram_pstore_info.buf = oops_data; nvram_pstore_info.bufsize = oops_data_sz; + spin_lock_init(&nvram_pstore_info.buf_lock); + rc = pstore_register(&nvram_pstore_info); if (rc != 0) pr_err("nvram: pstore_register() failed, defaults to " ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [powerpc] init nvram_pstore_info's buf_lock 2014-11-17 2:52 [PATCH powerpc] init nvram_pstore_info's buf_lock Li Zhong @ 2014-11-18 4:33 ` Michael Ellerman 2014-11-18 6:12 ` Li Zhong 0 siblings, 1 reply; 3+ messages in thread From: Michael Ellerman @ 2014-11-18 4:33 UTC (permalink / raw) To: Li Zhong, PowerPC email list; +Cc: Paul Mackerras On Mon, 2014-17-11 at 02:52:30 UTC, Li Zhong wrote: > It seems nvram_pstore_info's buf_lock is not initialized before > registering, which causes some strange behavior when trying to obtain > the lock during kdump process. What kind of strange behaviour? Does it still work and just print a warning? It's static, so I'd expect it to be unlocked by default. cheers ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [powerpc] init nvram_pstore_info's buf_lock 2014-11-18 4:33 ` [powerpc] " Michael Ellerman @ 2014-11-18 6:12 ` Li Zhong 0 siblings, 0 replies; 3+ messages in thread From: Li Zhong @ 2014-11-18 6:12 UTC (permalink / raw) To: Michael Ellerman; +Cc: Paul Mackerras, PowerPC email list On 二, 2014-11-18 at 15:33 +1100, Michael Ellerman wrote: > On Mon, 2014-17-11 at 02:52:30 UTC, Li Zhong wrote: > > It seems nvram_pstore_info's buf_lock is not initialized before > > registering, which causes some strange behavior when trying to obtain > > the lock during kdump process. > > What kind of strange behaviour? Does it still work and just print a warning? > > It's static, so I'd expect it to be unlocked by default. Yes, you are right. It still works. I saw it on a UP configuration, noticed the console stopped for a couple of seconds, then "lockup suspected" warning printed out, but then it continued to run. After some further checking, it seems working as designed for the UP spinlock debug, from the comments in spinlock_up.h * In the debug case, 1 means unlocked, 0 means locked. (the values * are inverted, to catch initialization bugs) So try lock fails, and lockup reported, but then arch_spin_lock() passes. Thanks, Zhong > > cheers > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-11-18 6:17 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-11-17 2:52 [PATCH powerpc] init nvram_pstore_info's buf_lock Li Zhong 2014-11-18 4:33 ` [powerpc] " Michael Ellerman 2014-11-18 6:12 ` Li Zhong
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