Re: [PATCH 3/3] ie31200_edac: Add driver

On 04/09/2014 06:44 PM, Luck, Tony wrote: So when the driver sees uncorrected errors, I'm also seeing them in my memory scanning program - so they correspond nicely. I didn't see anything logged in /var/log/mcelog, but I will update to the latest when possible. I wonder if there are some BIOS

Re: [PATCH 0/3] static keys: fix test/set races

On 06/29/2013 03:20 AM, Ingo Molnar wrote: * jba...@akamai.com jba...@akamai.com wrote: Hi, As pointed out by Andi Kleen, some static key users can be racy because they check the value of the key-enabled, and then subsequently update the branch direction. A number of call sites have 'higher'

Re: [PATCH 3/3] udp: make use of static_key_slow_set_true() interface

that led to this. Each change log should be sufficient to stand on its own. Explain why this patch is needed. And it's not about the use of a simpler API. It actually fixes a real bug. Signed-off-by: Jason Baron jba...@akamai.com --- net/ipv4/udp.c |9 - net/ipv6/udp.c |9

Re: [PATCH] Remove soon to be dead email address

some bounces. --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -4,8 +4,8 @@ /* * Jump label support * - * Copyright (C) 2009-2012 Jason Baron jba...@redhat.com - * Copyright (C) 2011-2012 Peter Zijlstra pzijl...@redhat.com + * Copyright (C) 2009-2012 Red Hat, Inc

[PATCH] intel_idle: use static_key to optimize idle enter/exit paths

If 'arat' is set in the cpuflags, we can avoid the checks for entering/exiting the tick broadcast code entirely. It would seem that this is a hot enough code path to make this worthwhile. I ran a few hackbench runs, and consistenly see reduced branches and cycles. Signed-off-by: Jason Baron jba

Re: [PATCH 0/3] static keys: fix test/set races

On 06/23/2014 10:28 PM, Steven Rostedt wrote: Cleaning out my INBOX I found this patch series. It seems to have been forgotten about. It ended up with Ingo and Peter agreeing with the way things should be done and I thought Jason was going to send an update. But that seems to never have

[PATCH v2 2/3] x38_edac: make use of lo_hi_readq()

Convert to the generic API. Signed-off-by: Jason Baron jba...@akamai.com --- drivers/edac/x38_edac.c | 15 ++- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/edac/x38_edac.c b/drivers/edac/x38_edac.c index 4891b45..e644b52 100644 --- a/drivers/edac/x38_edac.c

[PATCH v2 1/3] readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q

/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html p. 16) I can confirm this is true via several hard machine lockups. Thus, add explicit hi_lo_[readq|write]_q and lo_hi_[read|write]_q so that these uses are spelled out. Signed-off-by: Jason Baron jba...@akamai.com --- include/asm-generic/io-64

[PATCH v2 3/3] ie31200_edac: Introduce the driver

(sandy bridge) Signed-off-by: Jason Baron jba...@akamai.com --- drivers/edac/Kconfig| 7 + drivers/edac/Makefile | 1 + drivers/edac/ie31200_edac.c | 542 3 files changed, 550 insertions(+) create mode 100644 drivers/edac/ie31200_edac.c

[PATCH v2 0/3] Introduce ie31200_edac driver

) CPU E3-1270 V2 @ 3.50GHz : 8086:0158 (ivy bridge) CPU E31270 @ 3.40GHz : 8086:0108 (sandy bridge) Posted before as: https://lkml.org/lkml/2014/4/4/462 Patch against 3.16.0-rc2 Thanks, -Jason Changes since v1: - Cleanups and formatting based on previous feedback Jason Baron (3): readq/writeq

Re: [PATCH 0/3] static keys: fix test/set races

call sites a bit. Users of static keys should use either the inc/dec or the set_true/set_false API. Thanks, -Jason Jason Baron (3): static_keys: Add a static_key_slow_set_true()/false() interface sched: fix static keys race in sched_feat udp: make use of static_key_slow_set_true

[PATCH 2/2] sched: fix static_key race with sched_feat

. Take the i_mutex around these calls to resolve the race. Reported-by: Andi Kleen a...@firstfloor.org Signed-off-by: Jason Baron jba...@akamai.com --- kernel/sched/core.c | 5 + 1 file changed, 5 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3bdf01b..249c865 100644

[PATCH 0/2] sched: static_key sched_feat race + cleanup

Jason Baron (2): sched: remove extra static_key function indirection sched: fix static_key race with sched_feat kernel/sched/core.c | 5 + kernel/sched/sched.h | 12 +--- 2 files changed, 6 insertions(+), 11 deletions(-) -- 1.8.2.rc2 -- To unsubscribe from this list: send

[PATCH 1/2] sched: remove extra static_key function indirection

I think its a bit simpler without having to follow an extra layer of static inline fuctions. No functional change just cosmetic. Signed-off-by: Jason Baron jba...@akamai.com --- kernel/sched/sched.h | 12 +--- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/kernel/sched

Re: [PATCH] intel_idle: use static_key to optimize idle enter/exit paths

On 07/28/2014 04:38 PM, Len Brown wrote: On Fri, Jul 11, 2014 at 1:54 PM, Jason Baron jba...@akamai.com wrote: If 'arat' is set in the cpuflags, we can avoid the checks for entering/exiting the tick broadcast code entirely. It would seem that this is a hot enough code path to make

Re: [PATCH 1/1] jump_label: tidy jump_label_ratelimit.h

Yes, that looks good. While at it I grep'd the tree for 'CONFIG_JUMP_LABEL', and found some uses in the netfilter code which should probably be 'HAVE_JUMP_LABEL' as well. Thanks, -Jason On 08/20/2014 05:29 AM, Zhouyi Zhou wrote: jump_label_ratelimit.h is split from jump_label.h to enable the

Re: [PATCH 1/1] jump_label: tidy jump_label_ratelimit.h

On 08/20/2014 10:58 PM, Zhouyi Zhou wrote: I have submitted two patches according to you suggestions: https://lkml.org/lkml/2014/8/20/885 https://lkml.org/lkml/2014/8/20/883 Hope I have made them right Thanks - they look good to me. -Jason -- To unsubscribe from this list: send the line

[PATCH] powercap/rapl: add support for cpu model 0x3f

if the h/w simply doesn't support that, or if the driver could be improved here. In any case, adding the 0x3f makes the driver useful for me. Tested aginst cpu: Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz Signed-off-by: Jason Baron jba...@akamai.com --- drivers/powercap/intel_rapl.c | 1 + 1 file

Re: [PATCH] powercap/rapl: add support for cpu model 0x3f

On 08/13/2014 06:50 PM, Jacob Pan wrote: On Wed, 13 Aug 2014 20:33:26 + (GMT) Jason Baron jba...@akamai.com wrote: I've confirmed that monitoring the package power usage as well as setting power limits appear to be working as expected. However, I do see in the logs: [5.082632

Re: [RFC PATCH] Flipped jump labels

On 08/10/2014 12:07 PM, Borislav Petkov wrote: On Sun, Aug 10, 2014 at 05:45:15PM +0200, Ingo Molnar wrote: Indeed - but could we use that interface to cleanly expose the arch_static_branch_active() code you've written, or do we need new variants? We could probably. The thing is, if we want

Re: arm: JUMP_LABEL and DEBUG_SET_MODULE_RONX should be mutually exclusive?

On 10/15/2014 11:34 AM, Kees Cook wrote: On Wed, Oct 15, 2014 at 5:21 AM, Paolo Pisati p.pis...@gmail.com wrote: Hi, i keep hitting this with BRIDGE=m, JUMP_LABEL=y and DEBUG_SET_MODULE_RONX=y: I think my RO/NX patch series solves this. I sent a pull request, but I haven't seen any movement

Re: [PATCH 4/4] lib: Use seq_open_private() instead of seq_open()

On 08/29/2014 12:06 PM, Rob Jones wrote: Using seq_open_private() removes boilerplate code from ddebug_proc_open() Looks good. Acked-by: Jason Baron jba...@akamai.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org

Re: [PATCH] dynamic_debug: change __dynamic_foo_dbg return types to void

On 09/24/2014 02:17 PM, Joe Perches wrote: The return value is not used by callers of these functions so change the functions to return void. Acked-by: Jason Baron jba...@akamai.com Greg - can you pick this up? Thanks, -Jason -- To unsubscribe from this list: send the line unsubscribe

Re: [PATCH V4] kernel, add bug_on_warn

Hi Prarit, On 10/24/2014 08:53 AM, Prarit Bhargava wrote: There have been several times where I have had to rebuild a kernel to cause a panic when hitting a WARN() in the code in order to get a crash dump from a system. Sometimes this is easy to do, other times (such as in the case of a

Re: [PATCH V5] kernel, add panic_on_warn

On 10/28/2014 08:31 AM, Prarit Bhargava wrote: There have been several times where I have had to rebuild a kernel to cause a panic when hitting a WARN() in the code in order to get a crash dump from a system. Sometimes this is easy to do, other times (such as in the case of a remote admin) it

[RFC PATCH 0/5] Remove global locks from epoll

Fam Zheng: http://lwn.net/Articles/628828/ since these patches are somewhat invasive. Thanks, -Jason Jason Baron (5): epoll: Remove ep_call_nested() from ep_eventpoll_poll() epoll: Remove ep_call_nested() from ep_poll_safewake() epoll: Add ep_call_nested_nolock() epoll: Allow topology

[RFC PATCH 1/5] epoll: remove ep_call_nested() from ep_eventpoll_poll()

of a global spin_lock() that was in use in ep_call_nested(). Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 59 +++--- 1 file changed, 23 insertions(+), 36 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index d77f944

[RFC PATCH 4/5] epoll: Allow topology checks to be parallelized

of per-instance data structures, such that these topology checks can safely be made in parallel. In addition, we make use of the ep_call_nested_nolock(), which avoids the nested_calls-lock. This is safe here, since we are already holding the 'epmutex' across all of these calls. Signed-off-by: Jason

Re: [RFC PATCH 5/5] epoll: introduce epoll connected components (remove the epmutex)

On 01/15/2015 06:10 PM, Eric Wong wrote: Jason Baron jba...@akamai.com wrote: I've done a bit of performance evaluation on a dual socket, 10 core, hyper threading enabled box: Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz. For the simple epfdN-epfdN-pipefdN topology case where each thread has its

[RFC PATCH 2/5] epoll: remove ep_call_nested() from ep_poll_safewake()

CONFIG_DEBUG_LOCK_ALLOC is generally used for production, so this should provide a decent speedup for the cases that we care about. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 47 ++- 1 file changed, 18 insertions(+), 29 deletions(-) diff --git a/fs

[RFC PATCH 3/5] epoll: add ep_call_nested_nolock()

Add an ep_call_nested_nolock() variant which functions the same as the current ep_call_nested(), except it does not acquire any locks. This call wil be used by subsequent patches which have provide their own 'external' locking. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 33

[RFC PATCH 5/5] epoll: introduce epoll connected components (remove the epmutex)

. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c| 325 ++ include/linux/eventpoll.h | 52 +--- include/linux/fs.h| 3 + 3 files changed, 311 insertions(+), 69 deletions(-) diff --git a/fs/eventpoll.c b/fs

Re: [PATCH 1/2] sched/wait: add round robin wakeup mode

On 02/10/2015 04:03 AM, Peter Zijlstra wrote: On Mon, Feb 09, 2015 at 11:06:17PM -0500, Jason Baron wrote: On 02/09/2015 04:50 PM, Peter Zijlstra wrote: On Mon, Feb 09, 2015 at 08:05:57PM +, Jason Baron wrote: diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 852143a..17d1039

Re: [PATCH v2 0/2] Add epoll round robin wakeup mode

On 02/17/2015 04:09 PM, Andy Lutomirski wrote: On Tue, Feb 17, 2015 at 12:33 PM, Jason Baron jba...@akamai.com wrote: On 02/17/2015 02:46 PM, Andy Lutomirski wrote: On Tue, Feb 17, 2015 at 11:33 AM, Jason Baron jba...@akamai.com wrote: When we are sharing a wakeup source among multiple epoll

Re: [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/18/2015 11:33 AM, Ingo Molnar wrote: * Jason Baron jba...@akamai.com wrote: This has two main advantages: firstly it solves the O(N) (micro-)problem, but it also more evenly distributes events both between task-lists and within epoll groups as tasks as well. Its solving 2 issues

[PATCH v2 1/2] sched/wait: add round robin wakeup mode

this is not desirable. The WQ_FLAG_ROUND_ROBIN is restricted to being exclusive as well, otherwise we do not know who is being woken up. Signed-off-by: Jason Baron jba...@akamai.com --- include/linux/wait.h | 11 +++ kernel/sched/wait.c | 10 -- 2 files changed, 19 insertions(+), 2 deletions

[PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

this additional heuristic in order minimize wakeup latencies. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 25 - include/uapi/linux/eventpoll.h | 6 ++ 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/fs/eventpoll.c b/fs

Re: [PATCH v2 0/2] Add epoll round robin wakeup mode

On 02/17/2015 02:46 PM, Andy Lutomirski wrote: On Tue, Feb 17, 2015 at 11:33 AM, Jason Baron jba...@akamai.com wrote: When we are sharing a wakeup source among multiple epoll fds, we end up with thundering herd wakeups, since there is currently no way to add to the wakeup source exclusively

[PATCH v2 0/2] Add epoll round robin wakeup mode

epoll fds to a shared wakeup soruce. Depends on EPOLLEXCLUSIVE being set and must be specified with an EPOLL_CTL_ADD operation. Thanks, -Jason Jason Baron (2): sched/wait: add round robin wakeup mode epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN fs/eventpoll.c

Re: [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/18/2015 03:07 AM, Ingo Molnar wrote: * Jason Baron jba...@akamai.com wrote: Epoll file descriptors that are added to a shared wakeup source are always added in a non-exclusive manner. That means that when we have multiple epoll fds attached to a shared wakeup source they are all

Re: [PATCH 1/2] jump_label: Allow jump labels to be used in assembly

to KBUILD_AFLAGS. Signed-off-by: Anton Blanchard an...@samba.org (adding Steven) Acked-by: Jason Baron jba...@akamai.com The jump label stuff often gets picked up by Steve, but I guess this could go through the powerpc tree as well... Thanks, -Jason -- To unsubscribe from this list: send

[PATCH 0/2] Add epoll round robin wakeup mode

); printf(nohit is: %d\n, nohit); } Jason Baron (2): sched/wait: add round robin wakeup mode epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN fs/eventpoll.c | 25 - include/linux/wait.h | 11 +++ include/uapi/linux/eventpoll.h | 6

[PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

this additional heuristic in order minimize wakeup latencies. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 25 - include/uapi/linux/eventpoll.h | 6 ++ 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/fs/eventpoll.c b/fs

[PATCH 1/2] sched/wait: add round robin wakeup mode

this is not desirable. The WQ_FLAG_ROUND_ROBIN is restricted to being exclusive as well, otherwise we do not know who is being woken up. Signed-off-by: Jason Baron jba...@akamai.com --- include/linux/wait.h | 11 +++ kernel/sched/wait.c | 5 - 2 files changed, 15 insertions(+), 1 deletion

Re: [PATCH 1/2] sched/wait: add round robin wakeup mode

On 02/09/2015 04:50 PM, Peter Zijlstra wrote: On Mon, Feb 09, 2015 at 08:05:57PM +, Jason Baron wrote: diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 852143a..17d1039 100644 --- a/kernel/sched/wait.c +++ b/kernel/sched/wait.c @@ -71,8 +71,11 @@ static void __wake_up_common

Re: [PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/09/2015 11:49 PM, Eric Wong wrote: Jason Baron jba...@akamai.com wrote: On 02/09/2015 05:45 PM, Andy Lutomirski wrote: On Mon, Feb 9, 2015 at 1:32 PM, Jason Baron jba...@akamai.com wrote: On 02/09/2015 03:18 PM, Andy Lutomirski wrote: On 02/09/2015 12:06 PM, Jason Baron wrote: Epoll

Re: [PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/09/2015 03:18 PM, Andy Lutomirski wrote: On 02/09/2015 12:06 PM, Jason Baron wrote: Epoll file descriptors that are added to a shared wakeup source are always added in a non-exclusive manner. That means that when we have multiple epoll fds attached to a shared wakeup source they are all

Re: [PATCH 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/09/2015 05:45 PM, Andy Lutomirski wrote: On Mon, Feb 9, 2015 at 1:32 PM, Jason Baron jba...@akamai.com wrote: On 02/09/2015 03:18 PM, Andy Lutomirski wrote: On 02/09/2015 12:06 PM, Jason Baron wrote: Epoll file descriptors that are added to a shared wakeup source are always added

Re: [PATCH 3/3] powerpc: Include linux/jump_label.h to get HAVE_JUMP_LABEL define

On 01/07/2015 05:35 AM, Anton Blanchard wrote: Commit 1bc9e47aa8e4 (powerpc/jump_label: Use HAVE_JUMP_LABEL) converted uses of CONFIG_JUMP_LABEL to HAVE_JUMP_LABEL in some assembly files. HAVE_JUMP_LABEL is defined in linux/jump_label.h, so we need to include this or we always get the non

Re: [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/18/2015 12:51 PM, Ingo Molnar wrote: * Ingo Molnar mi...@kernel.org wrote: [...] However, I think the userspace API change is less clear since epoll_wait() doesn't currently have an 'input' events argument as epoll_ctl() does. ... but the change would be a bit clearer and somewhat

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 03/05/2015 04:15 AM, Ingo Molnar wrote: * Jason Baron jba...@akamai.com wrote: 2) We are using the wakeup in this case to 'assign' work more permanently to the thread. That is, in the case of a listen socket we then add the connected socket to the woken up threads local set of epoll

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 03/05/2015 04:15 AM, Ingo Molnar wrote: * Jason Baron jba...@akamai.com wrote: 2) We are using the wakeup in this case to 'assign' work more permanently to the thread. That is, in the case of a listen socket we then add the connected socket to the woken up threads local set of epoll

Re: [PATCH v4 0/9] epoll: Introduce new syscalls, epoll_ctl_batch and epoll_pwait1

On 03/09/2015 09:49 PM, Fam Zheng wrote: Benchmark for epoll_pwait1 == By running fio tests inside VM with both original and modified QEMU, we can compare their difference in performance. With a small VM setup [t1], the original QEMU (ppoll based) has an 4k read

Re: [PATCH v4 0/9] epoll: Introduce new syscalls, epoll_ctl_batch and epoll_pwait1

On 03/13/2015 07:31 AM, Fam Zheng wrote: On Thu, 03/12 11:02, Jason Baron wrote: On 03/09/2015 09:49 PM, Fam Zheng wrote: Hi, So it sounds like you are comparing original qemu code (which was using ppoll) vs. using epoll with these new syscalls. Curious if you have numbers comparing

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 02/27/2015 04:10 PM, Andrew Morton wrote: On Wed, 25 Feb 2015 11:27:04 -0500 Jason Baron jba...@akamai.com wrote: Libenzi inactive eventpoll appears to be without a dedicated maintainer since 2011 or so. Is there anyone who knows the code and its usages in detail and does final ABI

Re: [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

Hi, v3 of this series implements this idea using using a different approach: http://lkml.iu.edu/hypermail/linux/kernel/1502.3/00667.html If that still meets your needs it would be helpful to know in order to move this forward. Looking back at your posting, I was concerned about the test case

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 03/04/2015 07:02 PM, Ingo Molnar wrote: * Andrew Morton a...@linux-foundation.org wrote: On Fri, 27 Feb 2015 17:01:32 -0500 Jason Baron jba...@akamai.com wrote: I don't really understand the need for rotation/round-robin. We can solve the thundering herd via exclusive wakeups, but what

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 02/27/2015 04:31 PM, Jonathan Corbet wrote: On Fri, 27 Feb 2015 13:10:34 -0800 Andrew Morton a...@linux-foundation.org wrote: I don't really understand the need for rotation/round-robin. We can solve the thundering herd via exclusive wakeups, but what is the point in choosing to wake the

[PATCH v3 0/3] epoll: introduce round robin wakeup mode

epoll optimization for overflow list Jason Baron (3): sched/wait: add __wake_up_rotate() epoll: limit wakeups to the overflow list epoll: Add EPOLL_ROTATE mode fs/eventpoll.c | 52 +++--- include/linux/wait.h | 1 + include/uapi

[PATCH v3 1/3] sched/wait: add __wake_up_rotate()

results in the same thread woken up again and again. The first intended user of this functionality is epoll. Signed-off-by: Jason Baron jba...@akamai.com --- include/linux/wait.h | 1 + kernel/sched/wait.c | 27 +++ 2 files changed, 28 insertions(+) diff --git a/include/linux

[PATCH v3 3/3] epoll: Add EPOLL_ROTATE mode

. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 41 +++-- include/uapi/linux/eventpoll.h | 4 2 files changed, 39 insertions(+), 6 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index da84712..a8b06a1 100644

[PATCH v3 2/3] epoll: restrict wakeups to the overflow list

). However, we wish to add policies that are stateful (for example rotating wakeups among epoll sets), and these unnecessary wakeups cause unwanted transitions. Signed-off-by: Jason Baron jba...@akamai.com --- fs/eventpoll.c | 11 +-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git

Re: [PATCH v2 2/2] epoll: introduce EPOLLEXCLUSIVE and EPOLLROUNDROBIN

On 02/21/2015 07:24 PM, Eric Wong wrote: Jason Baron jba...@akamai.com wrote: On 02/18/2015 12:51 PM, Ingo Molnar wrote: * Ingo Molnar mi...@kernel.org wrote: [...] However, I think the userspace API change is less clear since epoll_wait() doesn't currently have an 'input' events argument

Re: [PATCH v3 0/3] epoll: introduce round robin wakeup mode

On 02/25/2015 02:38 AM, Ingo Molnar wrote: * Jason Baron jba...@akamai.com wrote: Hi, When we are sharing a wakeup source among multiple epoll fds, we end up with thundering herd wakeups, since there is currently no way to add to the wakeup source exclusively. This series introduces

softirq under reporting with CONFIG_NO_HZ_* and under syn flood ?

Hi, Creating a synflood via: 'hping3 -V -S -M 0 -p 80 --flood -y ip addr', when I have: CONFIG_NO_HZ_IDLE=y or CONFIG_NO_HZ_FULL=y set, and either: CONFIG_VIRT_CPU_ACCOUNTING_GEN=y or CONFIG_TICK_CPU_ACCOUNTING=y shows almost 0% cpu usage via top (or /proc/stat), whereas if I have turbostat

Re: epoll and multiple processes - eliminate unneeded process wake-ups

. Jason Baron was working on this (search LKML archives for EPOLLEXCLUSIVE, EPOLLROUNDROBIN, EPOLL_ROTATE) However, I was unconvinced about modifying epoll. Perhaps I may be more easily convinced about your mqueue case than his case for listen sockets, though[*] Yeah, so I implemented

Re: epoll and multiple processes - eliminate unneeded process wake-ups

On 08/05/2015 07:06 AM, Madars Vitolins wrote: Jason Baron @ 2015-08-04 18:02 rakstīja: On 08/03/2015 07:48 PM, Eric Wong wrote: Madars Vitolins m...@silodev.com wrote: Hi Folks, I am developing kind of open systems application, which uses multiple processes/executables where each of them

Re: [PATCH -v2 7/8] jump_label: Add selftest

/lib/test_jump_label.c @@ -0,0 +1,225 @@ +/* + * Kernel module for testing jump labels. + * + * Copyright 2015 Akamai Technologies Inc. All Rights Reserved + * + * Authors: + * Jason Baron jba...@akamai.com + * + * This software is licensed under the terms of the GNU General Public

Re: Kernel broken on processors without performance counters

On 07/22/2015 12:24 AM, Borislav Petkov wrote: On Tue, Jul 21, 2015 at 02:50:25PM -0400, Jason Baron wrote: hmmm...so this is a case where need to the default the branch to the out-of-line branch at boot. That is, we can't just enable the out-of-line branch at boot time, b/c it might be too

Re: Kernel broken on processors without performance counters

On 07/21/2015 12:12 PM, Peter Zijlstra wrote: On Tue, Jul 21, 2015 at 08:51:51AM -0700, Andy Lutomirski wrote: To clarify my (mis-)understanding: There are two degrees of freedom in a static_key. They can start out true or false, and they can be unlikely or likely. Are those two degrees

Re: Kernel broken on processors without performance counters

On 07/21/2015 02:15 PM, Borislav Petkov wrote: On Tue, Jul 21, 2015 at 06:12:15PM +0200, Peter Zijlstra wrote: Yes, if you start out false, you must be unlikely. If you start out true, you must be likely. We could maybe try and untangle that if there really is a good use case, but this is

Re: Kernel broken on processors without performance counters

On 07/24/2015 08:36 AM, Peter Zijlstra wrote: On Fri, Jul 24, 2015 at 12:56:02PM +0200, Peter Zijlstra wrote: On Thu, Jul 23, 2015 at 03:14:13PM -0400, Jason Baron wrote: +static enum jump_label_type jump_label_type(struct jump_entry *entry) +{ + struct static_key *key = static_key_cast

Re: Kernel broken on processors without performance counters

On 07/23/2015 06:42 AM, Peter Zijlstra wrote: On Wed, Jul 22, 2015 at 01:06:44PM -0400, Jason Baron wrote: Ok, So we could add all 4 possible initial states, where the branches would be: static_likely_init_true_branch(struct static_likely_init_true_key *key) static_likely_init_false_branch

Re: Kernel broken on processors without performance counters

On 07/23/2015 10:49 AM, Peter Zijlstra wrote: On Thu, Jul 23, 2015 at 04:33:08PM +0200, Peter Zijlstra wrote: Lemme finish this and I'll post it. Compile tested on x86_64 only.. Please have a look, I think you said I got some of the logic wrong, I've not double checked that. I'll go write

Re: Kernel broken on processors without performance counters

On 07/23/2015 01:08 PM, Peter Zijlstra wrote: On Thu, Jul 23, 2015 at 11:34:50AM -0400, Steven Rostedt wrote: On Thu, 23 Jul 2015 12:42:15 +0200 Peter Zijlstra pet...@infradead.org wrote: static __always_inline bool arch_static_branch_jump(struct static_key *key, bool inv) { if (!inv)

Re: [PATCH 1/2] dynamic_debug: fix boot parameters parse

On 10/27/2015 03:40 AM, Peter Chen wrote: > The parse_args will delete space between boot parameters, so > if we add dyndbg="file drivers/usb/* +p" at bootargs, the parse_args > will split it as three parameters, and only "file" is for dyndbg, > then below error will occur at ddebug, it causes all

Re: [RFC] unix: fix use-after-free in unix_dgram_poll()

On 10/28/2015 12:46 PM, Rainer Weikusat wrote: > Rainer Weikusat <r...@doppelsaurus.mobileactivedefense.com> writes: >> Jason Baron <jba...@akamai.com> writes: > > [...] > >>> 2) >>> >>> For the case of epoll() in edge triggered mo

Re: [PATCH] unix: avoid use-after-free in ep_remove_wait_queue

Hi Rainer, > + > +/* Needs sk unix state lock. After recv_ready indicated not ready, > + * establish peer_wait connection if still needed. > + */ > +static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other) > +{ > + int connected; > + > + connected =

Re: [PATCH] unix: avoid use-after-free in ep_remove_wait_queue

On 11/13/2015 01:51 PM, Rainer Weikusat wrote: [...] > > - if (unix_peer(other) != sk && unix_recvq_full(other)) { > - if (!timeo) { > - err = -EAGAIN; > - goto out_unlock; > - } > + if (unix_peer(sk) == other &&

Re: [PATCH] unix: avoid use-after-free in ep_remove_wait_queue (w/ Fixes:)

corresponding peer_wait queue. There's no way to forcibly deregister a > wait queue with epoll. > > Based on an idea by Jason Baron, the patch below changes the code such > that a wait_queue_t belonging to the client socket is enqueued on the > peer_wait queue of the server wheneve

Re: [PATCH] unix: avoid use-after-free in ep_remove_wait_queue

On 11/15/2015 01:32 PM, Rainer Weikusat wrote: > > That was my original idea. The problem with this is that the code > starting after the _lock and running until the main code path unlock has > to be executed in one go with the other lock held as the results of the > tests above this one may

Re: [PATCH] unix: avoid use-after-free in ep_remove_wait_queue

corresponding peer_wait queue. There's no way to forcibly deregister a > wait queue with epoll. > > Based on an idea by Jason Baron, the patch below changes the code such > that a wait_queue_t belonging to the client socket is enqueued on the > peer_wait queue of the server wheneve

Re: Use-after-free in ep_remove_wait_queue

On 11/06/2015 08:06 AM, Dmitry Vyukov wrote: > On Mon, Oct 12, 2015 at 2:17 PM, Dmitry Vyukov wrote: >> On Mon, Oct 12, 2015 at 2:14 PM, Eric Dumazet wrote: >>> On Mon, 2015-10-12 at 14:02 +0200, Michal Kubecek wrote: >>> Probably the issue

Re: [PATCH v2 1/3] unix: fix use-after-free in unix_dgram_poll()

On 10/18/2015 04:58 PM, Rainer Weikusat wrote: [...] > > The idea behind 'the wait queue' (insofar I'm aware of it) is that it > will be used as list of threads who need to be notified when the > associated event occurs. Since you seem to argue that the run-of-the-mill > algorithm is too slow

Re: [PATCH v2 1/3] unix: fix use-after-free in unix_dgram_poll()

On 10/12/2015 04:41 PM, Rainer Weikusat wrote: > Jason Baron <jba...@akamai.com> writes: >> On 10/05/2015 12:31 PM, Rainer Weikusat wrote: > > [...] > >>> Here's a more simple idea which _might_ work. The underlying problem >>> seems to be that the

[PATCH v3 3/3] net: unix: optimize wakeups in unix_dgram_recvmsg()

Now that connect() permanently registers a callback routine, we can induce extra overhead in unix_dgram_recvmsg(), which unconditionally wakes up its peer_wait queue on every receive. This patch makes the wakeup there conditional on there being waiters. Signed-off-by: Jason Baron <

[PATCH v3 0/3] net: unix: fix use-after-free

comments in 3/3 (Peter Zijlstra) -clean up unix_dgram_writable() function in 3/3 (Joe Perches) Jason Baron (3): net: unix: fix use-after-free in unix_dgram_poll() net: unix: Convert gc_flags to flags net: unix: optimize wakeups in unix_dgram_recvmsg() include/net/af_unix.h | 4 +- net/unix

[PATCH v3 1/3] net: unix: fix use-after-free in unix_dgram_poll()

ooglemail.com> Signed-off-by: Jason Baron <jba...@akamai.com> --- include/net/af_unix.h | 1 + net/unix/af_unix.c| 32 +++- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 4a167b3..9698aff 10

[PATCH v3 2/3] net: unix: Convert gc_flags to flags

Convert gc_flags to flags in perparation for the subsequent patch, which will make use of a flag bit for a non-gc purpose. Signed-off-by: Jason Baron <jba...@akamai.com> --- include/net/af_unix.h | 2 +- net/unix/garbage.c| 12 ++-- 2 files changed, 7 insertions(+), 7 del

Re: [PATCH v2 1/3] unix: fix use-after-free in unix_dgram_poll()

> > X-Signed-Off-By: Rainer Weikusat > Hi, So the patches I've posted and yours both use the idea of a relaying the remote peer wakeup via callbacks that are internal to the net/unix, such that we avoid exposing the remote peer wakeup to the external

[PATCH v4 2/3] net: unix: Convert gc_flags to flags

Convert gc_flags to flags in perparation for the subsequent patch, which will make use of a flag bit for a non-gc purpose. Signed-off-by: Jason Baron <jba...@akamai.com> --- include/net/af_unix.h | 2 +- net/unix/garbage.c| 12 ++-- 2 files changed, 7 insertions(+), 7 del

[PATCH v4 0/3] net: unix: fix use-after-free

if the peer socket has receive space v3: -beef up memory barrier comments in 3/3 (Peter Zijlstra) -clean up unix_dgram_writable() function in 3/3 (Joe Perches) Jason Baron (3): net: unix: fix use-after-free in unix_dgram_poll() net: unix: Convert gc_flags to flags net: unix: optimize wakeups

[PATCH v4 3/3] net: unix: optimize wakeups in unix_dgram_recvmsg()

/netdev/msg145533.html Signed-off-by: Jason Baron <jba...@akamai.com> --- include/net/af_unix.h | 1 + net/unix/af_unix.c| 92 +-- 2 files changed, 69 insertions(+), 24 deletions(-) diff --git a/include/net/af_unix.h b/include/net/af_

[PATCH v4 1/3] net: unix: fix use-after-free in unix_dgram_poll()

ooglemail.com> Signed-off-by: Jason Baron <jba...@akamai.com> --- include/net/af_unix.h | 1 + net/unix/af_unix.c| 32 +++- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 4a167b3..9698aff 10

Re: [PATCH v4 0/3] net: unix: fix use-after-free

On 10/11/2015 07:55 AM, David Miller wrote: > From: Jason Baron <jba...@akamai.com> > Date: Fri, 9 Oct 2015 00:15:59 -0400 > >> These patches are against mainline, I can re-base to net-next, please >> let me know. >> >> They have been tested against: https:

Re: [PATCH v4 1/3] net: unix: fix use-after-free in unix_dgram_poll()

On 10/09/2015 10:38 AM, Hannes Frederic Sowa wrote: > Hi, > > Jason Baron <jba...@akamai.com> writes: > >> The unix_dgram_poll() routine calls sock_poll_wait() not only for the wait >> queue associated with the socket s that we are poll'ing against, but al

Re: [PATCH v2 1/3] unix: fix use-after-free in unix_dgram_poll()

On 10/05/2015 12:31 PM, Rainer Weikusat wrote: > Jason Baron <jba...@akamai.com> writes: >> The unix_dgram_poll() routine calls sock_poll_wait() not only for the wait >> queue associated with the socket s that we are poll'ing against, but also >> calls >> sock_pol

Re: [PATCH v4 3/3] net: unix: optimize wakeups in unix_dgram_recvmsg()

gisters a callback routine, we can induce extra overhead in unix_dgram_recvmsg(), which unconditionally wakes up its peer_wait queue on every receive. This patch makes the wakeup there conditional on there being waiters. Tested using: http://www.spinics.net/lists/netdev/msg145533.html Signed-off-b

Re: Kernel broken on processors without performance counters

On 07/08/2015 01:37 PM, Andy Lutomirski wrote: On Wed, Jul 8, 2015 at 9:07 AM, Peter Zijlstra pet...@infradead.org wrote: On Wed, Jul 08, 2015 at 11:17:38AM -0400, Mikulas Patocka wrote: Hi I found out that the patch a66734297f78707ce39d756b656bfae861d53f62 breaks the kernel on processors

Re: Kernel broken on processors without performance counters

On 07/10/2015 10:13 AM, Peter Zijlstra wrote: On Wed, Jul 08, 2015 at 05:36:43PM -0700, Andy Lutomirski wrote: In what universe is static_key_false a reasonable name for a function that returns true if a static key is true? I think the current naming is almost maximally bad. The naming would

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