Messages in this thread |  | | Subject | Re: [PATCH 0/5] arm64: add the time namespace support | From | Vincenzo Frascino <> | Date | Mon, 17 Feb 2020 18:25:08 +0000 |
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Hi Andrei,
On 17/02/2020 15:34, Andrei Vagin wrote: > Vincenzo, could you take a look this patchset? >
Apologize for not getting to this yet. I will have a look at your patches during this week.
> On Tue, Feb 04, 2020 at 09:59:08AM -0800, Andrei Vagin wrote: >> Allocate the time namespace page among VVAR pages and add the logic >> to handle faults on VVAR properly. >> >> If a task belongs to a time namespace then the VVAR page which contains >> the system wide VDSO data is replaced with a namespace specific page >> which has the same layout as the VVAR page. That page has vdso_data->seq >> set to 1 to enforce the slow path and vdso_data->clock_mode set to >> VCLOCK_TIMENS to enforce the time namespace handling path. >> >> The extra check in the case that vdso_data->seq is odd, e.g. a concurrent >> update of the VDSO data is in progress, is not really affecting regular >> tasks which are not part of a time namespace as the task is spin waiting >> for the update to finish and vdso_data->seq to become even again. >> >> If a time namespace task hits that code path, it invokes the corresponding >> time getter function which retrieves the real VVAR page, reads host time >> and then adds the offset for the requested clock which is stored in the >> special VVAR page. >> >> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Dmitry Safonov <dima@arista.com> >> >> Andrei Vagin (5): >> arm64/vdso: use the fault callback to map vvar pages >> arm64/vdso: Zap vvar pages when switching to a time namespace >> arm64/vdso: Add time napespace page >> arm64/vdso: Handle faults on timens page >> arm64/vdso: Restrict splitting VVAR VMA >> >> arch/arm64/Kconfig | 1 + >> .../include/asm/vdso/compat_gettimeofday.h | 11 ++ >> arch/arm64/include/asm/vdso/gettimeofday.h | 8 ++ >> arch/arm64/kernel/vdso.c | 134 ++++++++++++++++-- >> arch/arm64/kernel/vdso/vdso.lds.S | 3 +- >> arch/arm64/kernel/vdso32/vdso.lds.S | 3 +- >> include/vdso/datapage.h | 1 + >> 7 files changed, 147 insertions(+), 14 deletions(-) >> >> -- >> 2.24.1 >>
-- Regards, Vincenzo [unhandled content-type:application/pgp-keys] |  |