I am so buried as to only be able to do new builds of cero once a week. Can the bad behavior be duplicated on a single core other sort of processor, like x86? Or merely boot up a x86 box in a single processor mode?
I'll try to get a new release out next sunday. On Sun, Jan 13, 2013 at 8:43 PM, Ketan Kulkarni <[email protected]> wrote: > Thanks Eric and Yuchung for taking care of the patch. I will test few more > TFO cases as well once this patch is built in cero. > > Thanks, > Ketan > > On Jan 14, 2013 9:37 AM, "Eric Dumazet" <[email protected]> wrote: >> >> Quite frankly I would just remove the BUG_ON() >> >> diff --git a/net/core/request_sock.c b/net/core/request_sock.c >> index c31d9e8..4425148 100644 >> --- a/net/core/request_sock.c >> +++ b/net/core/request_sock.c >> @@ -186,8 +186,6 @@ void reqsk_fastopen_remove(struct sock *sk, struct >> request_sock *req, >> struct fastopen_queue *fastopenq = >> inet_csk(lsk)->icsk_accept_queue.fastopenq; >> >> - BUG_ON(!spin_is_locked(&sk->sk_lock.slock) && >> !sock_owned_by_user(sk)); >> - >> tcp_sk(sk)->fastopen_rsk = NULL; >> spin_lock_bh(&fastopenq->lock); >> fastopenq->qlen--; >> >> >> >> On Sun, Jan 13, 2013 at 7:05 PM, Eric Dumazet <[email protected]> wrote: >>> >>> Oh well yes, this doesnt quite work on !SMP. >>> >>> And this kind of bug is frequent.... >>> >>> See following example : >>> >>> commit b9980cdcf2524c5fe15d8cbae9c97b3ed6385563 >>> Author: Hugh Dickins <[email protected]> >>> Date: Wed Feb 8 17:13:40 2012 -0800 >>> >>> mm: fix UP THP spin_is_locked BUGs >>> >>> Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y >>> CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always >>> false, >>> and so triggers some BUGs in Transparent HugePage codepaths. >>> >>> asm-generic/bug.h mentions this problem, and provides a >>> WARN_ON_SMP(x); >>> but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, >>> WARN_ON_SMP_ONCE, >>> VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing >>> VM_BUG_ONs. >>> >>> Signed-off-by: Hugh Dickins <[email protected]> >>> Cc: Andrea Arcangeli <[email protected]> >>> Cc: <[email protected]> >>> Signed-off-by: Andrew Morton <[email protected]> >>> Signed-off-by: Linus Torvalds <[email protected]> >>> >>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>> index b3ffc21..91d3efb 100644 >>> --- a/mm/huge_memory.c >>> +++ b/mm/huge_memory.c >>> @@ -2083,7 +2083,7 @@ static void collect_mm_slot(struct mm_slot >>> *mm_slot) >>> { >>> struct mm_struct *mm = mm_slot->mm; >>> >>> - VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock)); >>> + VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock)); >>> >>> >>> >>> >>> On Sun, Jan 13, 2013 at 1:39 PM, Felix Fietkau <[email protected]> wrote: >>>> >>>> On 2013-01-13 7:03 PM, Eric Dumazet wrote: >>>> > I suspect a bug in the spin_is_locked() implementation on your arch, >>>> > as >>>> > he socket lock should be held at this point. >>>> I don't think this is an arch implementation bug, this probably happens >>>> on all !SMP systems. See this bit from include/linux/spinlock_up.h: >>>> >>>> #define arch_spin_is_locked(lock) ((void)(lock), 0) >>>> >>>> - Felix >>>> >>> >> > > > _______________________________________________ > Cerowrt-devel mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/cerowrt-devel > -- Dave Täht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel
