* [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
@ 2013-11-12 20:52 Amit Pundir
2013-11-12 23:59 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Amit Pundir @ 2013-11-12 20:52 UTC (permalink / raw)
To: Arve Hjønnevåg, Rafael J. Wysocki, Alexander Viro
Cc: John Stultz, linux-fsdevel, linux-kernel, Android Kernel Team
ep_create_wakeup_source() reports ENOMEM if wakeup_source_register()
returns NULL. ep_create_wakeup_source() assumes that NULL is only
returned if we run into ENOMEM but NULL is also returned when
CONFIG_PM_SLEEP is disabled.
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
Changed in v2:
Using static inline functions instead of #ifdefs
---
fs/eventpoll.c | 3 +--
include/uapi/linux/eventpoll.h | 12 ++++++++++++
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 473e09d..10f9c43 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
goto error_tgt_fput;
/* Check if EPOLLWAKEUP is allowed */
- if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
- epds.events &= ~EPOLLWAKEUP;
+ ep_epollwakeup_check(&epds.events);
/*
* We have to check that the file structure underneath the file descriptor
diff --git a/include/uapi/linux/eventpoll.h b/include/uapi/linux/eventpoll.h
index 2c267bc..1d139c2 100644
--- a/include/uapi/linux/eventpoll.h
+++ b/include/uapi/linux/eventpoll.h
@@ -62,4 +62,16 @@ struct epoll_event {
} EPOLL_PACKED;
+#ifdef CONFIG_PM_SLEEP
+static inline void ep_epollwakeup_check(__u32 *epev)
+{
+ if ((*epev & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
+ *epev &= ~EPOLLWAKEUP;
+}
+#else
+static inline void ep_epollwakeup_check(__u32 *epev)
+{
+ *epev &= ~EPOLLWAKEUP;
+}
+#endif
#endif /* _UAPI_LINUX_EVENTPOLL_H */
--
1.7.10.4
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
2013-11-12 20:52 [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled Amit Pundir
@ 2013-11-12 23:59 ` Rafael J. Wysocki
2013-11-13 8:05 ` Amit Pundir
0 siblings, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2013-11-12 23:59 UTC (permalink / raw)
To: Amit Pundir
Cc: Arve Hjønnevåg, Alexander Viro, John Stultz,
linux-fsdevel, linux-kernel, Android Kernel Team
On Wednesday, November 13, 2013 02:22:28 AM Amit Pundir wrote:
> ep_create_wakeup_source() reports ENOMEM
That needs to be fixed too. I suppose we can make the wakeup_source_register()
stub for CONFIG_PM_SLEEP unset return ERR_PTR(-ENOSYS) or something like that
and ep_create_wakeup_source() return that instead of -ENOMEM. It looks like
eventpoll.c is the only user of it built for CONFIG_PM_SLEEP unset, but that
needs to be double checked.
> if wakeup_source_register()
> returns NULL. ep_create_wakeup_source() assumes that NULL is only
> returned if we run into ENOMEM but NULL is also returned when
> CONFIG_PM_SLEEP is disabled.
>
> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
> ---
> Changed in v2:
> Using static inline functions instead of #ifdefs
> ---
> fs/eventpoll.c | 3 +--
> include/uapi/linux/eventpoll.h | 12 ++++++++++++
> 2 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/fs/eventpoll.c b/fs/eventpoll.c
> index 473e09d..10f9c43 100644
> --- a/fs/eventpoll.c
> +++ b/fs/eventpoll.c
> @@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
> goto error_tgt_fput;
>
> /* Check if EPOLLWAKEUP is allowed */
> - if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
> - epds.events &= ~EPOLLWAKEUP;
> + ep_epollwakeup_check(&epds.events);
The "check" part of the name kind of suggests that the function will not change
things. What about ep_adjust_epollwakeup() or something along these lines?
And why don't you pass a pointer to epds to it? Wouldn't it be cleaner this way?
>
> /*
> * We have to check that the file structure underneath the file descriptor
> diff --git a/include/uapi/linux/eventpoll.h b/include/uapi/linux/eventpoll.h
> index 2c267bc..1d139c2 100644
> --- a/include/uapi/linux/eventpoll.h
> +++ b/include/uapi/linux/eventpoll.h
> @@ -62,4 +62,16 @@ struct epoll_event {
> } EPOLL_PACKED;
>
>
> +#ifdef CONFIG_PM_SLEEP
> +static inline void ep_epollwakeup_check(__u32 *epev)
> +{
> + if ((*epev & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
> + *epev &= ~EPOLLWAKEUP;
> +}
> +#else
> +static inline void ep_epollwakeup_check(__u32 *epev)
> +{
> + *epev &= ~EPOLLWAKEUP;
> +}
> +#endif
> #endif /* _UAPI_LINUX_EVENTPOLL_H */
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
2013-11-12 23:59 ` Rafael J. Wysocki
@ 2013-11-13 8:05 ` Amit Pundir
2013-11-13 21:44 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Amit Pundir @ 2013-11-13 8:05 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Arve Hjønnevåg, Alexander Viro, John Stultz,
linux-fsdevel, linux-kernel, Android Kernel Team
On 13 November 2013 05:29, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Wednesday, November 13, 2013 02:22:28 AM Amit Pundir wrote:
>> ep_create_wakeup_source() reports ENOMEM
>
> That needs to be fixed too. I suppose we can make the wakeup_source_register()
> stub for CONFIG_PM_SLEEP unset return ERR_PTR(-ENOSYS) or something like that
> and ep_create_wakeup_source() return that instead of -ENOMEM. It looks like
> eventpoll.c is the only user of it built for CONFIG_PM_SLEEP unset, but that
> needs to be double checked.
Instead of modifying wakeup_source_register() stub, what if I make
ep_create_wakeup_source() static inline as well and use its stub to
return -ENOSYS when CONFIG_PM_SLEEP is not set?
ep_create_wakeup_source() is used only in fs/eventpoll.c anyway.
>
>> if wakeup_source_register()
>> returns NULL. ep_create_wakeup_source() assumes that NULL is only
>> returned if we run into ENOMEM but NULL is also returned when
>> CONFIG_PM_SLEEP is disabled.
>>
>> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
>> ---
>> Changed in v2:
>> Using static inline functions instead of #ifdefs
>> ---
>> fs/eventpoll.c | 3 +--
>> include/uapi/linux/eventpoll.h | 12 ++++++++++++
>> 2 files changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/eventpoll.c b/fs/eventpoll.c
>> index 473e09d..10f9c43 100644
>> --- a/fs/eventpoll.c
>> +++ b/fs/eventpoll.c
>> @@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
>> goto error_tgt_fput;
>>
>> /* Check if EPOLLWAKEUP is allowed */
>> - if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
>> - epds.events &= ~EPOLLWAKEUP;
>> + ep_epollwakeup_check(&epds.events);
>
> The "check" part of the name kind of suggests that the function will not change
> things. What about ep_adjust_epollwakeup() or something along these lines?
I see couple of ep_set_* functions in eventpoll.c. Does it make sense
to have something like ep_set_epollwakeup()?
>
> And why don't you pass a pointer to epds to it? Wouldn't it be cleaner this way?
Ok.
Regards,
Amit Pundir
>
>>
>> /*
>> * We have to check that the file structure underneath the file descriptor
>> diff --git a/include/uapi/linux/eventpoll.h b/include/uapi/linux/eventpoll.h
>> index 2c267bc..1d139c2 100644
>> --- a/include/uapi/linux/eventpoll.h
>> +++ b/include/uapi/linux/eventpoll.h
>> @@ -62,4 +62,16 @@ struct epoll_event {
>> } EPOLL_PACKED;
>>
>>
>> +#ifdef CONFIG_PM_SLEEP
>> +static inline void ep_epollwakeup_check(__u32 *epev)
>> +{
>> + if ((*epev & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
>> + *epev &= ~EPOLLWAKEUP;
>> +}
>> +#else
>> +static inline void ep_epollwakeup_check(__u32 *epev)
>> +{
>> + *epev &= ~EPOLLWAKEUP;
>> +}
>> +#endif
>> #endif /* _UAPI_LINUX_EVENTPOLL_H */
>
> Thanks!
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
2013-11-13 8:05 ` Amit Pundir
@ 2013-11-13 21:44 ` Rafael J. Wysocki
2013-11-14 16:29 ` Amit Pundir
0 siblings, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2013-11-13 21:44 UTC (permalink / raw)
To: Amit Pundir
Cc: Arve Hjønnevåg, Alexander Viro, John Stultz,
linux-fsdevel, linux-kernel, Android Kernel Team
On Wednesday, November 13, 2013 01:35:38 PM Amit Pundir wrote:
> On 13 November 2013 05:29, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Wednesday, November 13, 2013 02:22:28 AM Amit Pundir wrote:
> >> ep_create_wakeup_source() reports ENOMEM
> >
> > That needs to be fixed too. I suppose we can make the wakeup_source_register()
> > stub for CONFIG_PM_SLEEP unset return ERR_PTR(-ENOSYS) or something like that
> > and ep_create_wakeup_source() return that instead of -ENOMEM. It looks like
> > eventpoll.c is the only user of it built for CONFIG_PM_SLEEP unset, but that
> > needs to be double checked.
>
> Instead of modifying wakeup_source_register() stub, what if I make
> ep_create_wakeup_source() static inline as well and use its stub to
> return -ENOSYS when CONFIG_PM_SLEEP is not set?
> ep_create_wakeup_source() is used only in fs/eventpoll.c anyway.
Well, you can do that too.
> >> if wakeup_source_register()
> >> returns NULL. ep_create_wakeup_source() assumes that NULL is only
> >> returned if we run into ENOMEM but NULL is also returned when
> >> CONFIG_PM_SLEEP is disabled.
> >>
> >> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
> >> ---
> >> Changed in v2:
> >> Using static inline functions instead of #ifdefs
> >> ---
> >> fs/eventpoll.c | 3 +--
> >> include/uapi/linux/eventpoll.h | 12 ++++++++++++
> >> 2 files changed, 13 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/fs/eventpoll.c b/fs/eventpoll.c
> >> index 473e09d..10f9c43 100644
> >> --- a/fs/eventpoll.c
> >> +++ b/fs/eventpoll.c
> >> @@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
> >> goto error_tgt_fput;
> >>
> >> /* Check if EPOLLWAKEUP is allowed */
> >> - if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
> >> - epds.events &= ~EPOLLWAKEUP;
> >> + ep_epollwakeup_check(&epds.events);
> >
> > The "check" part of the name kind of suggests that the function will not change
> > things. What about ep_adjust_epollwakeup() or something along these lines?
>
> I see couple of ep_set_* functions in eventpoll.c. Does it make sense
> to have something like ep_set_epollwakeup()?
This particular one doesn't really set anything. I suppose that a name like
"ep_take_care_of_epollwakeup" might be somewhat closer to what it really does ...
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
2013-11-13 21:44 ` Rafael J. Wysocki
@ 2013-11-14 16:29 ` Amit Pundir
2013-11-14 19:48 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Amit Pundir @ 2013-11-14 16:29 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Arve Hjønnevåg, Alexander Viro, John Stultz,
linux-fsdevel, linux-kernel, Android Kernel Team
On 14 November 2013 03:14, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> On Wednesday, November 13, 2013 01:35:38 PM Amit Pundir wrote:
>> On 13 November 2013 05:29, Rafael J. Wysocki <rjw@sisk.pl> wrote:
>> > On Wednesday, November 13, 2013 02:22:28 AM Amit Pundir wrote:
>> >> ep_create_wakeup_source() reports ENOMEM
>> >
>> > That needs to be fixed too. I suppose we can make the wakeup_source_register()
>> > stub for CONFIG_PM_SLEEP unset return ERR_PTR(-ENOSYS) or something like that
>> > and ep_create_wakeup_source() return that instead of -ENOMEM. It looks like
>> > eventpoll.c is the only user of it built for CONFIG_PM_SLEEP unset, but that
>> > needs to be double checked.
>>
>> Instead of modifying wakeup_source_register() stub, what if I make
>> ep_create_wakeup_source() static inline as well and use its stub to
>> return -ENOSYS when CONFIG_PM_SLEEP is not set?
>> ep_create_wakeup_source() is used only in fs/eventpoll.c anyway.
>
> Well, you can do that too.
>
On second thought we may skip modifying ep_create_wakeup_source() or
wakeup_source_register() altogether because once we drop EPOLLWAKEUP
from epoll events mask(if PM_SLEEP is unset) then I don't see us
running into ep_create_wakeup_source() again. And the only reason for
ep_create_wakeup_source() failure will be -ENOMEM as far as I can see.
>> >> if wakeup_source_register()
>> >> returns NULL. ep_create_wakeup_source() assumes that NULL is only
>> >> returned if we run into ENOMEM but NULL is also returned when
>> >> CONFIG_PM_SLEEP is disabled.
>> >>
>> >> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
>> >> ---
>> >> Changed in v2:
>> >> Using static inline functions instead of #ifdefs
>> >> ---
>> >> fs/eventpoll.c | 3 +--
>> >> include/uapi/linux/eventpoll.h | 12 ++++++++++++
>> >> 2 files changed, 13 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/fs/eventpoll.c b/fs/eventpoll.c
>> >> index 473e09d..10f9c43 100644
>> >> --- a/fs/eventpoll.c
>> >> +++ b/fs/eventpoll.c
>> >> @@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
>> >> goto error_tgt_fput;
>> >>
>> >> /* Check if EPOLLWAKEUP is allowed */
>> >> - if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
>> >> - epds.events &= ~EPOLLWAKEUP;
>> >> + ep_epollwakeup_check(&epds.events);
>> >
>> > The "check" part of the name kind of suggests that the function will not change
>> > things. What about ep_adjust_epollwakeup() or something along these lines?
>>
>> I see couple of ep_set_* functions in eventpoll.c. Does it make sense
>> to have something like ep_set_epollwakeup()?
>
> This particular one doesn't really set anything. I suppose that a name like
> "ep_take_care_of_epollwakeup" might be somewhat closer to what it really does ...
I'm running out of ideas on this one, lets go with
"ep_take_care_of_epollwakeup".
Regards,
Amit Pundir
>
> Thanks!
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled
2013-11-14 16:29 ` Amit Pundir
@ 2013-11-14 19:48 ` Rafael J. Wysocki
0 siblings, 0 replies; 6+ messages in thread
From: Rafael J. Wysocki @ 2013-11-14 19:48 UTC (permalink / raw)
To: Amit Pundir
Cc: Arve Hjønnevåg, Alexander Viro, John Stultz,
linux-fsdevel, linux-kernel, Android Kernel Team
On Thursday, November 14, 2013 09:59:44 PM Amit Pundir wrote:
> On 14 November 2013 03:14, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Wednesday, November 13, 2013 01:35:38 PM Amit Pundir wrote:
> >> On 13 November 2013 05:29, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> > On Wednesday, November 13, 2013 02:22:28 AM Amit Pundir wrote:
> >> >> ep_create_wakeup_source() reports ENOMEM
> >> >
> >> > That needs to be fixed too. I suppose we can make the wakeup_source_register()
> >> > stub for CONFIG_PM_SLEEP unset return ERR_PTR(-ENOSYS) or something like that
> >> > and ep_create_wakeup_source() return that instead of -ENOMEM. It looks like
> >> > eventpoll.c is the only user of it built for CONFIG_PM_SLEEP unset, but that
> >> > needs to be double checked.
> >>
> >> Instead of modifying wakeup_source_register() stub, what if I make
> >> ep_create_wakeup_source() static inline as well and use its stub to
> >> return -ENOSYS when CONFIG_PM_SLEEP is not set?
> >> ep_create_wakeup_source() is used only in fs/eventpoll.c anyway.
> >
> > Well, you can do that too.
> >
>
> On second thought we may skip modifying ep_create_wakeup_source() or
> wakeup_source_register() altogether because once we drop EPOLLWAKEUP
> from epoll events mask(if PM_SLEEP is unset) then I don't see us
> running into ep_create_wakeup_source() again. And the only reason for
> ep_create_wakeup_source() failure will be -ENOMEM as far as I can see.
OK
> >> >> if wakeup_source_register()
> >> >> returns NULL. ep_create_wakeup_source() assumes that NULL is only
> >> >> returned if we run into ENOMEM but NULL is also returned when
> >> >> CONFIG_PM_SLEEP is disabled.
> >> >>
> >> >> Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
> >> >> ---
> >> >> Changed in v2:
> >> >> Using static inline functions instead of #ifdefs
> >> >> ---
> >> >> fs/eventpoll.c | 3 +--
> >> >> include/uapi/linux/eventpoll.h | 12 ++++++++++++
> >> >> 2 files changed, 13 insertions(+), 2 deletions(-)
> >> >>
> >> >> diff --git a/fs/eventpoll.c b/fs/eventpoll.c
> >> >> index 473e09d..10f9c43 100644
> >> >> --- a/fs/eventpoll.c
> >> >> +++ b/fs/eventpoll.c
> >> >> @@ -1820,8 +1820,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
> >> >> goto error_tgt_fput;
> >> >>
> >> >> /* Check if EPOLLWAKEUP is allowed */
> >> >> - if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
> >> >> - epds.events &= ~EPOLLWAKEUP;
> >> >> + ep_epollwakeup_check(&epds.events);
> >> >
> >> > The "check" part of the name kind of suggests that the function will not change
> >> > things. What about ep_adjust_epollwakeup() or something along these lines?
> >>
> >> I see couple of ep_set_* functions in eventpoll.c. Does it make sense
> >> to have something like ep_set_epollwakeup()?
> >
> > This particular one doesn't really set anything. I suppose that a name like
> > "ep_take_care_of_epollwakeup" might be somewhat closer to what it really does ...
>
> I'm running out of ideas on this one, lets go with
> "ep_take_care_of_epollwakeup".
Well, that's fine by me, if no one else has any better ideas.
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-11-14 19:35 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2013-11-12 20:52 [RFC][PATCH v2] epoll: allow EPOLLWAKEUP flag if PM_SLEEP is enabled Amit Pundir
2013-11-12 23:59 ` Rafael J. Wysocki
2013-11-13 8:05 ` Amit Pundir
2013-11-13 21:44 ` Rafael J. Wysocki
2013-11-14 16:29 ` Amit Pundir
2013-11-14 19:48 ` Rafael J. Wysocki
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