Re: [PATCH tip/core/rcu 04/13] rcu: Don't disable preemption for Tiny and Tree RCU readers

2015-10-06 Thread Josh Triplett
On Tue, Oct 06, 2015 at 10:01:01AM -0700, Paul E. McKenney wrote: > On Tue, Oct 06, 2015 at 09:44:45AM -0700, Josh Triplett wrote: > > On Tue, Oct 06, 2015 at 09:13:39AM -0700, Paul E. McKenney wrote: > > > From: Boqun Feng <boqun.f...@gmail.com> > > > >

Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock()

2015-10-06 Thread Josh Triplett
On Tue, Oct 06, 2015 at 10:36:46AM -0700, Paul E. McKenney wrote: > On Tue, Oct 06, 2015 at 10:18:39AM -0700, Josh Triplett wrote: > > On Tue, Oct 06, 2015 at 09:13:42AM -0700, Paul E. McKenney wrote: > > > Currently, __srcu_read_lock() cannot be invoked from restricted > >

Re: [PATCH tip/core/rcu 0/13] percpu-rwsem patches for 4.4

2015-10-06 Thread Josh Triplett
terov. > > 13. Cleanup the CONFIG_PROVE_RCU checks, courtesy of Oleg Nesterov. For all 13: Reviewed-by: Josh Triplett <j...@joshtriplett.org> Regarding the rcu_sync infrastructure: odd that an atomic read on the reader proves ligher weight than rcu_read_lock()/rcu_read_unlo

Re: [PATCH tip/core/rcu 06/13] rcu: Add online/offline info to stall warning message

2015-10-06 Thread Josh Triplett
On Tue, Oct 06, 2015 at 09:13:41AM -0700, Paul E. McKenney wrote: > This commit makes the RCU CPU stall warning message print online/offline > indications immediately after the CPU number. A "?" indicates global > offline, a "," global online, and a "!" indicates RCU believes that the > CPU is

Re: [PATCH tip/core/rcu 0/13] Miscellaneous fixes for 4.4

2015-10-06 Thread Josh Triplett
.edu/amatveev/RLU_SOSP2015.pdf > > 12. Remove deprecated rcu_lockdep_assert(). (And a patch 13 not mentioned here.) I responded to patches 4, 6, and 10 with feedback; for the rest (and for those with the issues addressed): Reviewed-by: Josh Triplett <j...@joshtriplett.org> -- To unsubsc

Re: [PATCH tip/core/rcu 0/5] Documentation changes for 4.4

2015-10-06 Thread Josh Triplett
> 3.Update whatisRCU() to show rcu_dereference_protected(), > courtesy of Jason A. Donenfeld. > > 4.Catch up list of torture_type options. > > 5.Add lockless_dereference() to memory-barriers.txt. For all five: Reviewed-by: Josh Triplett <j...@joshtriplet

Re: [PATCH tip/core/rcu 1/4] rcutorture: Fix module unwind when bad torture_type specified

2015-10-06 Thread Josh Triplett
eview of rcu_torture_cleanup and the cur_ops->init() functions to verify that the dire comment about not using "goto unwind" doesn't actually apply (rcu_torture_cleanup *seems* to handle lack of init), this seems fine. Reviewed-by: Josh Triplett <j...@joshtriplett.org> > kernel/rcu/

Re: [PATCH tip/core/rcu 10/13] rcu: Add rcu_pointer_handoff()

2015-10-06 Thread Josh Triplett
On Tue, Oct 06, 2015 at 10:31:52AM -0700, Paul E. McKenney wrote: > On Tue, Oct 06, 2015 at 10:21:28AM -0700, Josh Triplett wrote: > > On Tue, Oct 06, 2015 at 09:13:45AM -0700, Paul E. McKenney wrote: > > > This commit adds an rcu_pointer_handoff() that is intended to mark >

Re: [PATCH tip/core/rcu 0/4] torture-test changes for 4.4

2015-10-06 Thread Josh Triplett
t; 3.Forgive non-plural arguments. > > 4.Fix module unwind when bad torture_type specified to locktorture. For all four: Reviewed-by: Josh Triplett <j...@joshtriplett.org> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message

Re: [PATCH tip/core/rcu 07/13] rcu: Move preemption disabling out of __srcu_read_lock()

2015-10-06 Thread Josh Triplett
On Tue, Oct 06, 2015 at 09:13:42AM -0700, Paul E. McKenney wrote: > Currently, __srcu_read_lock() cannot be invoked from restricted > environments because it contains calls to preempt_disable() and > preempt_enable(), both of which can invoke lockdep, which is a bad > idea in some restricted

Re: [Tech-board-discuss] Linux Foundation Technical Advisory Board Elections and Nomination process

2015-10-06 Thread Josh Triplett
I'll be present in-person at Kernel Summit for the election. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCH] kselftest: replace $(RM) with rm -f command

2015-10-03 Thread Josh Triplett
On Sat, Oct 03, 2015 at 02:11:57PM +, Mathieu Desnoyers wrote: > - On Oct 3, 2015, at 12:38 AM, dvhart dvh...@infradead.org wrote: > > > On Mon, Sep 28, 2015 at 03:16:53AM +, Mathieu Desnoyers wrote: > >> - On Sep 27, 2015, at 10:10 PM, Wang Long long.wangl...@huawei.com > >>

Re: [PATCH] kselftest: replace $(RM) with rm -f command

2015-10-03 Thread Josh Triplett
On Sat, Oct 03, 2015 at 02:11:57PM +, Mathieu Desnoyers wrote: > - On Oct 3, 2015, at 12:38 AM, dvhart dvh...@infradead.org wrote: > > > On Mon, Sep 28, 2015 at 03:16:53AM +, Mathieu Desnoyers wrote: > >> - On Sep 27, 2015, at 10:10 PM, Wang Long long.wangl...@huawei.com > >>

Re: [PATCH 04/13] Always expose MAP_UNINITIALIZED to userspace

2015-09-15 Thread Josh Triplett
On Tue, Sep 15, 2015 at 12:42:00PM +0300, Kirill A. Shutemov wrote: > On Mon, Sep 14, 2015 at 10:19:19PM -0700, Josh Triplett wrote: > > On Tue, Sep 15, 2015 at 03:23:58AM +0300, Kirill A. Shutemov wrote: > > > On Mon, Sep 14, 2015 at 03:50:38PM -0700, Palmer Dabbelt wrote:

Re: [PATCH 04/13] Always expose MAP_UNINITIALIZED to userspace

2015-09-15 Thread Josh Triplett
On Tue, Sep 15, 2015 at 12:42:00PM +0300, Kirill A. Shutemov wrote: > On Mon, Sep 14, 2015 at 10:19:19PM -0700, Josh Triplett wrote: > > On Tue, Sep 15, 2015 at 03:23:58AM +0300, Kirill A. Shutemov wrote: > > > On Mon, Sep 14, 2015 at 03:50:38PM -0700, Palmer Dabbelt wrote:

Re: [PATCH 04/13] Always expose MAP_UNINITIALIZED to userspace

2015-09-14 Thread Josh Triplett
without user separation (for instance, without CONFIG_MULTIUSER) can reasonably use MAP_UNINITIALIZED. > P.S. MAP_UNINITIALIZED itself looks very broken to me. I probably need dig > mailing list on why it was allowed. That's what the config option *and* explicit flag are for; there are more th

Re: [PATCH 04/13] Always expose MAP_UNINITIALIZED to userspace

2015-09-14 Thread Josh Triplett
without user separation (for instance, without CONFIG_MULTIUSER) can reasonably use MAP_UNINITIALIZED. > P.S. MAP_UNINITIALIZED itself looks very broken to me. I probably need dig > mailing list on why it was allowed. That's what the config option *and* explicit flag are for; there are more th

Re: [PATCH] kernel: make rcu/tree_trace.c explicitly non-modular

2015-08-25 Thread Josh Triplett
96b54a2 (""Tree RCU": scalable > classic RCU implementation") since it is not needed here either. > > We leave some tags like MODULE_AUTHOR for documentation purposes. > > Cc: "Paul E. McKenney" > Cc: Josh Triplett > Cc: Steven Rostedt > Cc: Mathi

Re: [PATCH] kernel: make rcu/tree_trace.c explicitly non-modular

2015-08-25 Thread Josh Triplett
either. We leave some tags like MODULE_AUTHOR for documentation purposes. Cc: Paul E. McKenney paul...@linux.vnet.ibm.com Cc: Josh Triplett j...@joshtriplett.org Cc: Steven Rostedt rost...@goodmis.org Cc: Mathieu Desnoyers mathieu.desnoy...@efficios.com Cc: Lai Jiangshan jiangshan

Re: [PATCH] x86, vsyscall: add CONFIG to control default

2015-08-12 Thread Josh Triplett
On Wed, Aug 12, 2015 at 05:55:19PM -0700, Kees Cook wrote: > Most modern systems can run with vsyscall=none. In an effort to provide > a way for build-time defaults to lack legacy settings, this adds a new > CONFIG to select the type of vsyscall mapping to use, similar to the > existing "vsyscall"

Re: [PATCH] x86, vsyscall: add CONFIG to control default

2015-08-12 Thread Josh Triplett
On Wed, Aug 12, 2015 at 05:55:19PM -0700, Kees Cook wrote: Most modern systems can run with vsyscall=none. In an effort to provide a way for build-time defaults to lack legacy settings, this adds a new CONFIG to select the type of vsyscall mapping to use, similar to the existing vsyscall

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-08-01 Thread Josh Triplett
On Fri, Jul 31, 2015 at 09:56:46PM -0700, H. Peter Anvin wrote: > On 07/31/2015 09:32 PM, Josh Triplett wrote: > > > > Sure, agreed. But I really hope we don't create new kernel ABIs that > > involve constructs like that. > > > > It's worth noting I have pushe

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-08-01 Thread Josh Triplett
On Fri, Jul 31, 2015 at 09:56:46PM -0700, H. Peter Anvin wrote: On 07/31/2015 09:32 PM, Josh Triplett wrote: Sure, agreed. But I really hope we don't create new kernel ABIs that involve constructs like that. It's worth noting I have pushed for auto-marshalling in general for a long

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
from_user and > > copy_param_struct on appropriate sets of __user parameters identified as > > such in a structured text file seems quite sufficient. (Plus > > automatically generating syscalls.h from that.) > > If a param struct does the trick, then I agree. It's when you start >

Re: [PATCHv3 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
d-off-by: David Drysdale > Reviewed-by: Michael Kerrisk > Reviewed-by: Eric B Munson > Reviewed-by: Kees Cook > Reviewed-by: Randy Dunlap Other than the change to the mention of capabilities, this now looks ready to me. With that item fixed: Reviewed-by: Josh Triplett > Doc

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
On Fri, Jul 31, 2015 at 10:48:32AM +0100, David Drysdale wrote: > On Thu, Jul 30, 2015 at 7:50 PM, Josh Triplett wrote: > > On Thu, Jul 30, 2015 at 08:52:11AM +0100, David Drysdale wrote: > >> Add a document describing the process of adding a new system call, > >> inc

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
syscalls.h from that.) If a param struct does the trick, then I agree. It's when you start having lists and other variable-size stuff that it gets messier. Sure, agreed. But I really hope we don't create new kernel ABIs that involve constructs like that. - Josh Triplett -- To unsubscribe from

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
On Fri, Jul 31, 2015 at 10:48:32AM +0100, David Drysdale wrote: On Thu, Jul 30, 2015 at 7:50 PM, Josh Triplett j...@joshtriplett.org wrote: On Thu, Jul 30, 2015 at 08:52:11AM +0100, David Drysdale wrote: Add a document describing the process of adding a new system call, including the need

Re: [PATCHv3 1/1] Documentation: describe how to add a system call

2015-07-31 Thread Josh Triplett
. With that item fixed: Reviewed-by: Josh Triplett j...@joshtriplett.org Documentation/adding-syscalls.txt | 531 ++ 1 file changed, 531 insertions(+) create mode 100644 Documentation/adding-syscalls.txt diff --git a/Documentation/adding-syscalls.txt

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 06:02:34PM -0700, Josh Triplett wrote: > On Thu, Jul 30, 2015 at 01:03:43PM -0700, Kees Cook wrote: > > On Thu, Jul 30, 2015 at 12:04 PM, Josh Triplett > > wrote: > > > On Thu, Jul 30, 2015 at 11:21:54AM -0700, Kees Cook wrote: > > >>

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 01:03:43PM -0700, Kees Cook wrote: > On Thu, Jul 30, 2015 at 12:04 PM, Josh Triplett wrote: > > On Thu, Jul 30, 2015 at 11:21:54AM -0700, Kees Cook wrote: > >> I like this, it's a good description of both options. I'm still biased > >> about t

Re: [PATCH] x86/mm, efi: Check for valid image type

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 06:33:41PM +0200, Sebastian Andrzej Siewior wrote: > On 07/29/2015 06:41 PM, Josh Triplett wrote: > > >> This is correct. However I miss the point of saving the image in the > >> first place. From what I see is that I have now 272 KiB in memory w

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
tampered with). - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 08:52:11AM +0100, David Drysdale wrote: > Add a document describing the process of adding a new system call, > including the need for a flags argument for future compatibility, and > covering 32-bit/64-bit concerns (albeit in an x86-centric way). > > Signed-off-by: David

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
you don't need param_4, don't use the version of the structure that has param_4. That also means the kernel doesn't need to copy and read those values. Either approach works, though. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel"

Re: [PATCH tip/core/rcu 02/19] rcu: Remove CONFIG_RCU_CPU_STALL_INFO

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 08:13:41AM -0700, Paul E. McKenney wrote: > On Thu, Jul 30, 2015 at 02:49:55PM +0200, Peter Zijlstra wrote: > > On Fri, Jul 17, 2015 at 04:29:07PM -0700, Paul E. McKenney wrote: > > > From: "Paul E. McKenney" > > > > > > The CONFIG_RCU_CPU_STALL_INFO has been default-y

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 01:03:43PM -0700, Kees Cook wrote: On Thu, Jul 30, 2015 at 12:04 PM, Josh Triplett j...@joshtriplett.org wrote: On Thu, Jul 30, 2015 at 11:21:54AM -0700, Kees Cook wrote: I like this, it's a good description of both options. I'm still biased about the approach: I

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 06:02:34PM -0700, Josh Triplett wrote: On Thu, Jul 30, 2015 at 01:03:43PM -0700, Kees Cook wrote: On Thu, Jul 30, 2015 at 12:04 PM, Josh Triplett j...@joshtriplett.org wrote: On Thu, Jul 30, 2015 at 11:21:54AM -0700, Kees Cook wrote: I like this, it's a good

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
with). - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
means the kernel doesn't need to copy and read those values. Either approach works, though. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

Re: [PATCH tip/core/rcu 02/19] rcu: Remove CONFIG_RCU_CPU_STALL_INFO

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 08:13:41AM -0700, Paul E. McKenney wrote: On Thu, Jul 30, 2015 at 02:49:55PM +0200, Peter Zijlstra wrote: On Fri, Jul 17, 2015 at 04:29:07PM -0700, Paul E. McKenney wrote: From: Paul E. McKenney paul...@linux.vnet.ibm.com The CONFIG_RCU_CPU_STALL_INFO has been

Re: [PATCHv2 1/1] Documentation: describe how to add a system call

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 08:52:11AM +0100, David Drysdale wrote: Add a document describing the process of adding a new system call, including the need for a flags argument for future compatibility, and covering 32-bit/64-bit concerns (albeit in an x86-centric way). Signed-off-by: David

Re: [PATCH] x86/mm, efi: Check for valid image type

2015-07-30 Thread Josh Triplett
On Thu, Jul 30, 2015 at 06:33:41PM +0200, Sebastian Andrzej Siewior wrote: On 07/29/2015 06:41 PM, Josh Triplett wrote: This is correct. However I miss the point of saving the image in the first place. From what I see is that I have now 272 KiB in memory which are never used again

Re: [PATCH] x86/mm, efi: Check for valid image type

2015-07-29 Thread Josh Triplett
place after a kexec, unless we have some way to know that it's > > actually valid. > > So you assume that the information from ACPI is always correct then? > The pointer is correct, the information it points to is no longer. > > If we run always under EFI then it looks like

Re: [PATCH] x86/mm, efi: Check for valid image type

2015-07-29 Thread Josh Triplett
on kexec entry. This hint is set via setup_data / SETUP_EFI since commit 1fec053369 (x86/efi: Pass necessary EFI data for kexec via setup_data). So maybe we could use this to check if we run under kexec or not. That sounds like a sensible fix; don't try to parse the BGRT if efi_setup. - Josh Triplett

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-27 Thread Josh Triplett
that was one of the cases they covered. While that might be possible to reduce, it doesn't sound like it can go away entirely. :) - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-27 Thread Josh Triplett
like it can go away entirely. :) - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-25 Thread Josh Triplett
On Sat, Jul 25, 2015 at 02:24:02PM -0700, Davidlohr Bueso wrote: > On Sat, 2015-07-25 at 12:47 -0700, Josh Triplett wrote: > > I certainly agree that it doesn't make sense to make all architectures > > select SRCU, if an unremovable core kernel feature uses SRCU. If > > poss

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-25 Thread Josh Triplett
in, though. Is there any chance at all of the shrinker mechanism becoming optional? At first glance, it seems reasonably separate from the rest of mm, in that if it didn't exist and shrinking didn't happen, the rest of mm still works. If that happened, MM_SHRINKER could select SRCU. If that's n

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-25 Thread Josh Triplett
On Sat, Jul 25, 2015 at 02:24:02PM -0700, Davidlohr Bueso wrote: On Sat, 2015-07-25 at 12:47 -0700, Josh Triplett wrote: I certainly agree that it doesn't make sense to make all architectures select SRCU, if an unremovable core kernel feature uses SRCU. If possible, I'd really like

Re: linux-next: build failure after merge of the akpm-current tree

2015-07-25 Thread Josh Triplett
symbol MM_SHRINKER that's always y and does select SRCU, to preserve SRCU's modularity for the moment while not forcing every architecture to select it. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org

Re: [RFC PATCH] thread_local_abi system call: caching current CPU number (x86)

2015-07-17 Thread Josh Triplett
pass non-zero, the pointer must be valid or you get -EFAULT (or an actual segfault). - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [RFC PATCH] thread_local_abi system call: caching current CPU number (x86)

2015-07-17 Thread Josh Triplett
= 0 if thread_local_abi = null? saving a branch doesn't seem like a good reason to do that; however, it *is* the convention across other calls: if you pass 0, the pointer is ignored, but if you pass non-zero, the pointer must be valid or you get -EFAULT (or an actual segfault). - Josh Triplett

LKML archives at UofI down?

2015-07-15 Thread Josh Triplett
The LKML archives once present at http://lkml.iu.edu/hypermail/linux/kernel/index.html seem to be down; http://lkml.iu.edu/hypermail/ appears empty. Does anyone know what happened to it? - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" i

LKML archives at UofI down?

2015-07-15 Thread Josh Triplett
The LKML archives once present at http://lkml.iu.edu/hypermail/linux/kernel/index.html seem to be down; http://lkml.iu.edu/hypermail/ appears empty. Does anyone know what happened to it? - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body

Re: [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones

2015-07-01 Thread Josh Triplett
On Tue, Jun 30, 2015 at 08:37:01PM -0700, Paul E. McKenney wrote: > On Tue, Jun 30, 2015 at 05:42:14PM -0700, Josh Triplett wrote: > > On Tue, Jun 30, 2015 at 05:15:58PM -0700, Paul E. McKenney wrote: > > > On Tue, Jun 30, 2015 at 04:46:33PM -0700, j...@joshtriplett.org wrote: &

Re: [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones

2015-07-01 Thread Josh Triplett
On Tue, Jun 30, 2015 at 08:37:01PM -0700, Paul E. McKenney wrote: On Tue, Jun 30, 2015 at 05:42:14PM -0700, Josh Triplett wrote: On Tue, Jun 30, 2015 at 05:15:58PM -0700, Paul E. McKenney wrote: On Tue, Jun 30, 2015 at 04:46:33PM -0700, j...@joshtriplett.org wrote: On Tue, Jun 30, 2015

Re: [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones

2015-06-30 Thread Josh Triplett
en again, perhaps the more relevant concern would be why drivers use > > expedited grace periods in the first place. > > Networking uses expedited grace periods when RTNL is held to reduce > contention on that lock. Wait, what? Why is anything using traditional (non-S) RCU while

Re: [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones

2015-06-30 Thread Josh Triplett
is held? Several other places have used it to minimize user-visible grace-period slowdown. But there are probably places that would be better served doing something different. That is after all the common case for most synchronization primitives. ;-) Sounds likely. :) - Josh Triplett

Re: arch linux with gcc 5.1.0 doesn't like include/linux/rcutiny.h

2015-06-15 Thread Josh Triplett
btuseness of the error message? Agreed. Can you reproduce this with a preprocessed file ("make kernel/rcu/rcutorture.i" first), and then provide that file in a bug report to GCC? - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the bo

Re: arch linux with gcc 5.1.0 doesn't like include/linux/rcutiny.h

2015-06-15 Thread Josh Triplett
report to GCC? - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCH 2/2] x86/asm/entry/32: Remove unnecessary optimization in stub32_clone

2015-06-04 Thread Josh Triplett
On Thu, Jun 04, 2015 at 12:07:31PM +0200, Denys Vlasenko wrote: > On 06/03/2015 06:38 PM, Josh Triplett wrote: > > On Wed, Jun 03, 2015 at 03:58:50PM +0200, Denys Vlasenko wrote: > >> Really swap arguments #4 and #5 in stub32_clone instead of "optimizing" > &

Re: [PATCH 2/2] x86/asm/entry/32: Remove unnecessary optimization in stub32_clone

2015-06-04 Thread Josh Triplett
On Thu, Jun 04, 2015 at 12:07:31PM +0200, Denys Vlasenko wrote: On 06/03/2015 06:38 PM, Josh Triplett wrote: On Wed, Jun 03, 2015 at 03:58:50PM +0200, Denys Vlasenko wrote: Really swap arguments #4 and #5 in stub32_clone instead of optimizing it into a move. Yes, tls_val is currently

Re: [PATCH 2/2] x86/asm/entry/32: Remove unnecessary optimization in stub32_clone

2015-06-03 Thread Josh Triplett
le or two on an expensive syscall like > clone() is way below noise floor, and this optimization is simply not worth > the obfuscation of logic. [...] > This is a resend. > > There was a patch by Josh Triplett > "x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bi

Re: [PATCH 2/2] x86/asm/entry/32: Remove unnecessary optimization in stub32_clone

2015-06-03 Thread Josh Triplett
like clone() is way below noise floor, and this optimization is simply not worth the obfuscation of logic. [...] This is a resend. There was a patch by Josh Triplett x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit sent on May 11, which does the same thing as part of a bigger

Re: [RFC v1] tree-wide: remove "select FW_LOADER" uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 09:29:51PM +, James Bottomley wrote: > On Mon, 2015-05-25 at 12:29 -0700, Josh Triplett wrote: > > On Mon, May 25, 2015 at 07:07:14PM +, James Bottomley wrote: > > > On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: > > > > On M

Re: [RFC v1] tree-wide: remove "select FW_LOADER" uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 07:07:14PM +, James Bottomley wrote: > On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: > > On Mon, May 25, 2015 at 12:55:17PM +0200, Paul Bolle wrote: > > > On Fri, 2015-05-22 at 14:43 -0700, j...@joshtriplett.org wrote: > > > >

Re: [RFC v1] tree-wide: remove "select FW_LOADER" uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 08:25:35PM +0200, Paul Bolle wrote: > On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: > > I don't mean cyclic dependencies (for which Kconfig should just report > > an error, ideally including the full list of symbols forming the cycle). > > &g

Re: [RFC v1] tree-wide: remove "select FW_LOADER" uses

2015-05-25 Thread Josh Triplett
r than having to look at the list of dependencies of a symbol, search for that symbol, remember the path the search showed, and browse there manually. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.o

Re: [RFC v1] tree-wide: remove select FW_LOADER uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 08:25:35PM +0200, Paul Bolle wrote: On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: I don't mean cyclic dependencies (for which Kconfig should just report an error, ideally including the full list of symbols forming the cycle). I mean that Kconfig should

Re: [RFC v1] tree-wide: remove select FW_LOADER uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 07:07:14PM +, James Bottomley wrote: On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: On Mon, May 25, 2015 at 12:55:17PM +0200, Paul Bolle wrote: On Fri, 2015-05-22 at 14:43 -0700, j...@joshtriplett.org wrote: Ideally, someone should teach Kconfig

Re: [RFC v1] tree-wide: remove select FW_LOADER uses

2015-05-25 Thread Josh Triplett
of dependencies of a symbol, search for that symbol, remember the path the search showed, and browse there manually. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http

Re: [RFC v1] tree-wide: remove select FW_LOADER uses

2015-05-25 Thread Josh Triplett
On Mon, May 25, 2015 at 09:29:51PM +, James Bottomley wrote: On Mon, 2015-05-25 at 12:29 -0700, Josh Triplett wrote: On Mon, May 25, 2015 at 07:07:14PM +, James Bottomley wrote: On Mon, 2015-05-25 at 10:54 -0700, Josh Triplett wrote: On Mon, May 25, 2015 at 12:55:17PM +0200, Paul

Re: [RFC v1] tree-wide: remove "select FW_LOADER" uses

2015-05-22 Thread Josh Triplett
ink ideally we should have *every* visible Kconfig option always pulled in by "depends on" rather than "select", with visibility and recursion handled by smarter tools. That said, meddle not in the internals of Kconfig, for it has many unshorn yaks (and yaccs). - Josh Trip

Re: [RFC v1] tree-wide: remove select FW_LOADER uses

2015-05-22 Thread Josh Triplett
tools. That said, meddle not in the internals of Kconfig, for it has many unshorn yaks (and yaccs). - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org

Re: [RFC PATCH] percpu system call: fast userspace percpu critical sections

2015-05-21 Thread Josh Triplett
getcpu() for "lock; cmpxchg" > we reach of speedup of 5.4x for load-store+tls-cache vs > "lock; cmpxchg"+vdso-getcpu. > > I'm sending this out to trigger discussion, and hopefully to see > Paul and Andrew's patches being posted publicly at some point, so

Re: [RFC PATCH] percpu system call: fast userspace percpu critical sections

2015-05-21 Thread Josh Triplett
a flags argument. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: Nature of ext4 corruption fixed by recent patch?

2015-05-20 Thread Josh Triplett
d as a short-term workaround until that change goes into the Debian kernel. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: Nature of ext4 corruption fixed by recent patch?

2015-05-20 Thread Josh Triplett
goes into the Debian kernel. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: Nature of ext4 corruption fixed by recent patch?

2015-05-19 Thread Josh Triplett
ubtle data corruptors tend to be highly timing > depend, and very hard to find. Sometimes these bugs can hang around > for years before they are found and fixed. The flip side is that > fortunately, they tend to strike very rarely. ...lucky me. > It's also why I'm very > grateful for

Re: Nature of ext4 corruption fixed by recent patch?

2015-05-19 Thread Josh Triplett
. :-) Indeed. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCH] x86: Align jump targets to 1 byte boundaries

2015-05-17 Thread Josh Triplett
On Sun, May 17, 2015 at 07:34:29AM +0200, Ingo Molnar wrote: > > * Josh Triplett wrote: > > > On Mon, Sep 17, 2001 at 07:00:00AM +, Ingo Molnar wrote: > > > * Denys Vlasenko wrote: > > > > > What do you guys think about this? I think we should ser

Re: [PATCH] x86: Align jump targets to 1 byte boundaries

2015-05-17 Thread Josh Triplett
On Sun, May 17, 2015 at 07:34:29AM +0200, Ingo Molnar wrote: * Josh Triplett j...@joshtriplett.org wrote: On Mon, Sep 17, 2001 at 07:00:00AM +, Ingo Molnar wrote: * Denys Vlasenko dvlas...@redhat.com wrote: What do you guys think about this? I think we should seriously

Re: [PATCH] x86: Align jump targets to 1 byte boundaries

2015-05-15 Thread Josh Triplett
sidered including -falign-labels=1 as well? Does that make a difference on top of the other three. Finally, it looks like -Os already implies all four of those, as well as a few others, so unfortunately the code size benefits don't actually apply to the tiniest kernels, which already eff

Re: [PATCH] x86: Align jump targets to 1 byte boundaries

2015-05-15 Thread Josh Triplett
like -Os already implies all four of those, as well as a few others, so unfortunately the code size benefits don't actually apply to the tiniest kernels, which already effectively incorporate this change. Oh well. - Josh Triplett -- To unsubscribe from this list: send the line unsubscribe linux

[PATCH 4/5] kconfig: Introduce "showif" to factor out conditions on visibility

2015-05-14 Thread Josh Triplett
me thing as "if" but for visibility expressions rather than dependencies. Every symbol in a "showif expr ... endif" block effectively has "if expr" added to its prompt. Signed-off-by: Josh Triplett Acked-by: Paul E. McKenney --- scripts/kconfig/menu.c

[PATCH 5/5] init/Kconfig.expert: Factor out "if EXPERT" conditions using showif

2015-05-14 Thread Josh Triplett
Use the new showif construct to simplify the expert menu. Now, making a symbol no longer invisible when !EXPERT requires moving it out of the EXPERT menu, which makes it more difficult to break the EXPERT menu. Signed-off-by: Josh Triplett Acked-by: Paul E. McKenney --- init/Kconfig.expert

[PATCH 3/5] kconfig: Regenerate parser with current Bison prior to making changes

2015-05-14 Thread Josh Triplett
Before making changes to the parser, regenerate the parser with current Bison to avoid mixing those changes with those produced by updating Bison. Signed-off-by: Josh Triplett --- scripts/kconfig/zconf.tab.c_shipped | 1244 --- 1 file changed, 561 insertions

[PATCH 2/5] init/Kconfig: Split expert menu into a separate file, init/Kconfig.expert

2015-05-14 Thread Josh Triplett
init/Kconfig.expert, to make this harder to do accidentally, and to break up the exceedingly long init/Kconfig a bit. Signed-off-by: Josh Triplett --- init/Kconfig| 232 +--- init/Kconfig.expert | 231

[PATCH 1/5] init/Kconfig: Fix break in middle of EXPERT menu

2015-05-14 Thread Josh Triplett
_TRACING kernels, make it more configurable") Signed-off-by: Josh Triplett --- init/Kconfig | 20 ++-- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index dc24dec..e2f16f1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1341,6 +13

Re: [PATCH v2] x86: Preserve iopl on fork and execve

2015-05-14 Thread Josh Triplett
a patch series that does exactly that, compiling out the syscalls as well as the underlying architecture-specific infrastructure. (Saves quite a bit of space, too.) It still needs some more detailed x86 architecture review. Peter, Ingo? Would you be interested in taking (an updated version of) tha

Re: [RFC PATCH v6] Documentation/arch: Add Documentation/arch-features.txt

2015-05-14 Thread Josh Triplett
On Thu, May 14, 2015 at 12:16:15PM +0200, Ingo Molnar wrote: > > * Josh Triplett wrote: > > > On Wed, May 13, 2015 at 09:27:57AM -0700, Josh Triplett wrote: > > > > > How likely is this to get out of date? Are people going to > > > remembe

[PATCH 2/5] init/Kconfig: Split expert menu into a separate file, init/Kconfig.expert

2015-05-14 Thread Josh Triplett
this harder to do accidentally, and to break up the exceedingly long init/Kconfig a bit. Signed-off-by: Josh Triplett j...@joshtriplett.org --- init/Kconfig| 232 +--- init/Kconfig.expert | 231

[PATCH 5/5] init/Kconfig.expert: Factor out if EXPERT conditions using showif

2015-05-14 Thread Josh Triplett
Use the new showif construct to simplify the expert menu. Now, making a symbol no longer invisible when !EXPERT requires moving it out of the EXPERT menu, which makes it more difficult to break the EXPERT menu. Signed-off-by: Josh Triplett j...@joshtriplett.org Acked-by: Paul E. McKenney paul

[PATCH 3/5] kconfig: Regenerate parser with current Bison prior to making changes

2015-05-14 Thread Josh Triplett
Before making changes to the parser, regenerate the parser with current Bison to avoid mixing those changes with those produced by updating Bison. Signed-off-by: Josh Triplett j...@joshtriplett.org --- scripts/kconfig/zconf.tab.c_shipped | 1244 --- 1 file changed

[PATCH 4/5] kconfig: Introduce showif to factor out conditions on visibility

2015-05-14 Thread Josh Triplett
... endif block effectively has if expr added to its prompt. Signed-off-by: Josh Triplett j...@joshtriplett.org Acked-by: Paul E. McKenney paul...@linux.vnet.ibm.com --- scripts/kconfig/menu.c | 4 +- scripts/kconfig/zconf.gperf | 1 + scripts/kconfig

[PATCH 1/5] init/Kconfig: Fix break in middle of EXPERT menu

2015-05-14 Thread Josh Triplett
configurable) Signed-off-by: Josh Triplett j...@joshtriplett.org --- init/Kconfig | 20 ++-- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index dc24dec..e2f16f1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1341,6 +1341,16 @@ config

Re: [RFC PATCH v6] Documentation/arch: Add Documentation/arch-features.txt

2015-05-14 Thread Josh Triplett
On Thu, May 14, 2015 at 12:16:15PM +0200, Ingo Molnar wrote: * Josh Triplett j...@joshtriplett.org wrote: On Wed, May 13, 2015 at 09:27:57AM -0700, Josh Triplett wrote: How likely is this to get out of date? Are people going to remember to patch this when they add a feature

Re: [PATCH v2] x86: Preserve iopl on fork and execve

2015-05-14 Thread Josh Triplett
as well as the underlying architecture-specific infrastructure. (Saves quite a bit of space, too.) It still needs some more detailed x86 architecture review. Peter, Ingo? Would you be interested in taking (an updated version of) that patch series for the next merge window? - Josh Triplett

[PATCH 4/4] kconfig: Introduce "showif" to factor out conditions on visibility

2015-05-13 Thread Josh Triplett
ERT requires moving it out of the EXPERT menu, which makes it more difficult to break the EXPERT menu. Signed-off-by: Josh Triplett --- init/Kconfig.expert | 44 +-- scripts/kconfig/menu.c | 4 +- scripts/kconfig/zconf.gperf |

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