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2016-09-30u64_stats: Introduce IRQs disabled helpersFrederic Weisbecker1-21/+24
Introduce light versions of u64_stats helpers for context where either preempt or IRQs are disabled. This way we can make this library usable by scheduler irqtime accounting which currenty implement its ad-hoc version. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-04tcp: fix lockdep splat in tcp_snd_una_update()Eric Dumazet1-0/+14
tcp_snd_una_update() and tcp_rcv_nxt_update() call u64_stats_update_begin() either from process context or BH handler. This triggers a lockdep splat on 32bit & SMP builds. We could add u64_stats_update_begin_bh() variant but this would slow down 32bit builds with useless local_disable_bh() and local_enable_bh() pairs, since we own the socket lock at this point. I add sock_owned_by_me() helper to have proper lockdep support even on 64bit builds, and new u64_stats_update_begin_raw() and u64_stats_update_end_raw methods. Fixes: c10d9310edf5 ("tcp: do not assume TCP code is non preemptible") Reported-by: Fabio Estevam <festevam@gmail.com> Diagnosed-by: Francois Romieu <romieu@fr.zoreil.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-16net: make u64_stats_init() a functionEric Dumazet1-3/+4
Using a function instead of a macro is cleaner and remove following W=1 warnings (extract) In file included from net/ipv6/ip6_vti.c:29:0: net/ipv6/ip6_vti.c: In function ‘vti6_dev_init_gen’: include/linux/netdevice.h:2029:18: warning: variable ‘stat’ set but not used [-Wunused-but-set-variable] typeof(type) *stat; \ ^ net/ipv6/ip6_vti.c:862:16: note: in expansion of macro ‘netdev_alloc_pcpu_stats’ dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); ^ CC [M] net/ipv6/sit.o In file included from net/ipv6/sit.c:30:0: net/ipv6/sit.c: In function ‘ipip6_tunnel_init’: include/linux/netdevice.h:2029:18: warning: variable ‘stat’ set but not used [-Wunused-but-set-variable] typeof(type) *stat; \ ^ Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-15net: Replace u64_stats_fetch_begin_bh to u64_stats_fetch_begin_irqEric W. Biederman1-8/+8
Replace the bh safe variant with the hard irq safe variant. We need a hard irq safe variant to deal with netpoll transmitting packets from hard irq context, and we need it in most if not all of the places using the bh safe variant. Except on 32bit uni-processor the code is exactly the same so don't bother with a bh variant, just have a hard irq safe variant that everyone can use. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-06net: Explicitly initialize u64_stats_sync structures for lockdepJohn Stultz1-0/+7
In order to enable lockdep on seqcount/seqlock structures, we must explicitly initialize any locks. The u64_stats_sync structure, uses a seqcount, and thus we need to introduce a u64_stats_init() function and use it to initialize the structure. This unfortunately adds a lot of fairly trivial initialization code to a number of drivers. But the benefit of ensuring correctness makes this worth while. Because these changes are required for lockdep to be enabled, and the changes are quite trivial, I've not yet split this patch out into 30-some separate patches, as I figured it would be better to get the various maintainers thoughts on how to best merge this change along with the seqcount lockdep enablement. Feedback would be appreciated! Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: James Morris <jmorris@namei.org> Cc: Jesse Gross <jesse@nicira.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mirko Lindner <mlindner@marvell.com> Cc: Patrick McHardy <kaber@trash.net> Cc: Roger Luethi <rl@hellgate.ch> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Simon Horman <horms@verge.net.au> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Wensong Zhang <wensong@linux-vs.org> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2010-11-29Kill off a bunch of warning: ‘inline’ is not at beginning of declarationJesper Juhl1-6/+6
These warnings are spewed during a build of a 'allnoconfig' kernel (especially the ones from u64_stats_sync.h show up a lot) when building with -Wextra (which I often do).. They are a) annoying b) easy to get rid of. This patch kills them off. include/linux/u64_stats_sync.h:70:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:77:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:84:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:96:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:115:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:127:1: warning: ‘inline’ is not at beginning of declaration kernel/time.c:241:1: warning: ‘inline’ is not at beginning of declaration kernel/time.c:257:1: warning: ‘inline’ is not at beginning of declaration kernel/perf_event.c:4513:1: warning: ‘inline’ is not at beginning of declaration mm/page_alloc.c:4012:1: warning: ‘inline’ is not at beginning of declaration Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-06-29net: u64_stats_fetch_begin_bh() and u64_stats_fetch_retry_bh()Eric Dumazet1-15/+44
- Must disable preemption in case of 32bit UP in u64_stats_fetch_begin() and u64_stats_fetch_retry() - Add new u64_stats_fetch_begin_bh() and u64_stats_fetch_retry_bh() for network usage, disabling BH on 32bit UP only. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-29net: u64_stats_sync improvementsEric Dumazet1-1/+5
- Add a comment about interrupts: 6) If counter might be written by an interrupt, readers should block interrupts. - Fix a typo in sample of use. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-23net: Introduce u64_stats_sync infrastructureEric Dumazet1-0/+107
To properly implement 64bits network statistics on 32bit or 64bit hosts, we provide one new type and four methods, to ease conversions. Stats producer should use following template granted it already got an exclusive access to counters (include/linux/u64_stats_sync.h contains some documentation about details) u64_stats_update_begin(&stats->syncp); stats->bytes64 += len; stats->packets64++; u64_stats_update_end(&stats->syncp); While a consumer should use following template to get consistent snapshot : u64 tbytes, tpackets; unsigned int start; do { start = u64_stats_fetch_begin(&stats->syncp); tbytes = stats->bytes64; tpackets = stats->packets64; } while (u64_stats_fetch_retry(&stats->lock, syncp)); Suggested by David Miller, and comments courtesy of Nick Piggin. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>