Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 08:28 PM, Darren Hart wrote: > > And as a follow-on, what is the reason for FUTEX_LOCK_PI only using > > CLOCK_REALTIME? It seems reasonable to me that a user may want to wait a > > specific amount of time, regardless of wall

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 08:28 PM, Darren Hart wrote: > > And as a follow-on, what is the reason for FUTEX_LOCK_PI only using > > CLOCK_REALTIME? It seems reasonable to me that a user may want to wait a > > specific amount of time, regardless of wall

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/24/2016 11:52 AM, Thomas Gleixner wrote: On Fri, 24 Jun 2016, Michael Kerrisk (man-pages) wrote: By the way, I just realized something that wasn't initially obvious to me, and documented it in the futex(2) man page: Note: for FUTEX_WAIT, timeout is interpreted as a

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/24/2016 11:52 AM, Thomas Gleixner wrote: On Fri, 24 Jun 2016, Michael Kerrisk (man-pages) wrote: By the way, I just realized something that wasn't initially obvious to me, and documented it in the futex(2) man page: Note: for FUTEX_WAIT, timeout is interpreted as a

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Fri, 24 Jun 2016, Michael Kerrisk (man-pages) wrote: > By the way, I just realized something that wasn't initially obvious > to me, and documented it in the futex(2) man page: > > Note: for FUTEX_WAIT, timeout is interpreted as a > relative value. This differs

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Fri, 24 Jun 2016, Michael Kerrisk (man-pages) wrote: > By the way, I just realized something that wasn't initially obvious > to me, and documented it in the futex(2) man page: > > Note: for FUTEX_WAIT, timeout is interpreted as a > relative value. This differs

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 09:53 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 08:35:15PM +0200, Michael Kerrisk (man-pages) wrote: Hi Darren, On 06/23/2016 06:16 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Michael Kerrisk (man-pages)

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 09:53 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 08:35:15PM +0200, Michael Kerrisk (man-pages) wrote: Hi Darren, On 06/23/2016 06:16 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Michael Kerrisk (man-pages)

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 12:55:15PM -0700, Darren Hart wrote: > On Thu, Jun 23, 2016 at 08:41:09PM +0200, Michael Kerrisk (man-pages) wrote: > > On 06/23/2016 08:28 PM, Darren Hart wrote: > > > On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > > > > On Thu, 23 Jun 2016, Darren Hart

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 12:55:15PM -0700, Darren Hart wrote: > On Thu, Jun 23, 2016 at 08:41:09PM +0200, Michael Kerrisk (man-pages) wrote: > > On 06/23/2016 08:28 PM, Darren Hart wrote: > > > On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > > > > On Thu, 23 Jun 2016, Darren Hart

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 08:41:09PM +0200, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 08:28 PM, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > > > On Thu, 23 Jun 2016, Darren Hart wrote: > > > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 08:41:09PM +0200, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 08:28 PM, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > > > On Thu, 23 Jun 2016, Darren Hart wrote: > > > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 08:35:15PM +0200, Michael Kerrisk (man-pages) wrote: > Hi Darren, > > On 06/23/2016 06:16 PM, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > > > On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > > > > On 06/23/2016 09:18

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 08:35:15PM +0200, Michael Kerrisk (man-pages) wrote: > Hi Darren, > > On 06/23/2016 06:16 PM, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > > > On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > > > > On 06/23/2016 09:18

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 08:28 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: In my opinion, we should treat the timeout value as relative for FUTEX_WAIT

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 08:28 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: In my opinion, we should treat the timeout value as relative for FUTEX_WAIT

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi Darren, On 06/23/2016 06:16 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: On 06/23/2016 09:18 AM, Thomas Gleixner wrote: Once upon a time, you told me the following: On 15 May 2014 at 16:14,

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi Darren, On 06/23/2016 06:16 PM, Darren Hart wrote: On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: On 06/23/2016 09:18 AM, Thomas Gleixner wrote: Once upon a time, you told me the following: On 15 May 2014 at 16:14,

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > On Thu, 23 Jun 2016, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > > In my opinion, we should treat the timeout value as relative for FUTEX_WAIT > > regardless of the CLOCK used. > >

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 07:26:52PM +0200, Thomas Gleixner wrote: > On Thu, 23 Jun 2016, Darren Hart wrote: > > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > > In my opinion, we should treat the timeout value as relative for FUTEX_WAIT > > regardless of the CLOCK used. > >

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Darren Hart wrote: > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > In my opinion, we should treat the timeout value as relative for FUTEX_WAIT > regardless of the CLOCK used. Which requires even more changes as you have to select which clock you are using

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Darren Hart wrote: > On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > In my opinion, we should treat the timeout value as relative for FUTEX_WAIT > regardless of the CLOCK used. Which requires even more changes as you have to select which clock you are using

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > > On 06/23/2016 09:18 AM, Thomas Gleixner wrote: > > Once upon a time, you told me the following: > > > > On 15 May 2014 at 16:14, Thomas Gleixner

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, Jun 23, 2016 at 03:40:36PM +0200, Thomas Gleixner wrote: > On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > > On 06/23/2016 09:18 AM, Thomas Gleixner wrote: > > Once upon a time, you told me the following: > > > > On 15 May 2014 at 16:14, Thomas Gleixner wrote: > > > On Thu, 15

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 09:18 AM, Thomas Gleixner wrote: > Once upon a time, you told me the following: > > On 15 May 2014 at 16:14, Thomas Gleixner wrote: > > On Thu, 15 May 2014, Michael Kerrisk (man-pages) wrote: > > > And

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Thu, 23 Jun 2016, Michael Kerrisk (man-pages) wrote: > On 06/23/2016 09:18 AM, Thomas Gleixner wrote: > Once upon a time, you told me the following: > > On 15 May 2014 at 16:14, Thomas Gleixner wrote: > > On Thu, 15 May 2014, Michael Kerrisk (man-pages) wrote: > > > And that universe would

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 09:18 AM, Thomas Gleixner wrote: On Wed, 22 Jun 2016, Darren Hart wrote: However, I don't think the patch below is correct. The existing logic determines the type of timeout based on the futex_op when it should instead determine the type of timeout based on the

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi Darren, On 06/23/2016 06:48 AM, Darren Hart wrote: On Mon, Jun 20, 2016 at 04:26:52PM +0200, Matthieu CASTET wrote: Hi, the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it change to syscall to an equivalent to FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME with a bitset of

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On 06/23/2016 09:18 AM, Thomas Gleixner wrote: On Wed, 22 Jun 2016, Darren Hart wrote: However, I don't think the patch below is correct. The existing logic determines the type of timeout based on the futex_op when it should instead determine the type of timeout based on the

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi Darren, On 06/23/2016 06:48 AM, Darren Hart wrote: On Mon, Jun 20, 2016 at 04:26:52PM +0200, Matthieu CASTET wrote: Hi, the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it change to syscall to an equivalent to FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME with a bitset of

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Wed, 22 Jun 2016, Darren Hart wrote: > However, I don't think the patch below is correct. The existing logic > determines the type of timeout based on the futex_op when it should instead > determine the type of timeout based on the FUTEX_CLOCK_REALTIME flag. No. > My reading of the man page

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Wed, 22 Jun 2016, Darren Hart wrote: > However, I don't think the patch below is correct. The existing logic > determines the type of timeout based on the futex_op when it should instead > determine the type of timeout based on the FUTEX_CLOCK_REALTIME flag. No. > My reading of the man page

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Mon, Jun 20, 2016 at 04:26:52PM +0200, Matthieu CASTET wrote: > Hi, > > the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it > change to syscall to an equivalent to FUTEX_WAIT_BITSET | > FUTEX_CLOCK_REALTIME with a bitset of FUTEX_BITSET_MATCH_ANY. > > It seems wrong to me,

Re: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Mon, Jun 20, 2016 at 04:26:52PM +0200, Matthieu CASTET wrote: > Hi, > > the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it > change to syscall to an equivalent to FUTEX_WAIT_BITSET | > FUTEX_CLOCK_REALTIME with a bitset of FUTEX_BITSET_MATCH_ANY. > > It seems wrong to me,

futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi, the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it change to syscall to an equivalent to FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME with a bitset of FUTEX_BITSET_MATCH_ANY. It seems wrong to me, because in case of FUTEX_WAIT, in "SYSCALL_DEFINE6(futex", we convert relative

futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Hi, the commit 337f13046ff03717a9e99675284a817527440a49 is saying that it change to syscall to an equivalent to FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME with a bitset of FUTEX_BITSET_MATCH_ANY. It seems wrong to me, because in case of FUTEX_WAIT, in "SYSCALL_DEFINE6(futex", we convert relative

[tip:locking/core] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

FUTEX_CLOCK_REALTIME with FUTEX_WAIT op While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask

[tip:locking/core] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

Sun, 20 Dec 2015 12:43:25 +0100 futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a si

Re: [PATCH] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Fri, 18 Dec 2015, Darren Hart wrote: While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask

[PATCH] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask of FUTEX_BITSET_MATCH_ANY). As such, I

Re: [PATCH] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

On Fri, 18 Dec 2015, Darren Hart wrote: While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask

[PATCH] futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op

While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask of FUTEX_BITSET_MATCH_ANY). As such, I