On 10/9/20 9:21 AM, Jens Axboe wrote: > On 10/9/20 2:01 AM, Miroslav Benes wrote: >> On Thu, 8 Oct 2020, Oleg Nesterov wrote: >> >>> On 10/05, Jens Axboe wrote: >>>> >>>> Hi, >>>> >>>> The goal is this patch series is to decouple TWA_SIGNAL based task_work >>>> from real signals and signal delivery. >>> >>> I think TIF_NOTIFY_SIGNAL can have more users. Say, we can move >>> try_to_freeze() from get_signal() to tracehook_notify_signal(), kill >>> fake_signal_wake_up(), and remove freezing() from recalc_sigpending(). >>> >>> Probably the same for TIF_PATCH_PENDING, klp_send_signals() can use >>> set_notify_signal() rather than signal_wake_up(). >> >> Yes, that was my impression from the patch set too, when I accidentally >> noticed it. >> >> Jens, could you CC our live patching ML when you submit v4, please? It >> would be a nice cleanup. > > Definitely, though it'd be v5 at this point. But we really need to get > all archs supporting TIF_NOTIFY_SIGNAL first. Once we have that, there's > a whole slew of cleanups that'll fall out naturally: > > - Removal of JOBCTL_TASK_WORK > - Removal of special path for TWA_SIGNAL in task_work > - TIF_PATCH_PENDING can be converted and then removed > - try_to_freeze() cleanup that Oleg mentioned > > And probably more I'm not thinking of right now :-) Here's the current series, I took a stab at converting all archs to support TIF_NOTIFY_SIGNAL so we have a base to build on top of. Most of them were straight forward, but I need someone to fixup powerpc, verify arm and s390. But it's a decent start I think, and means that we can drop various bits as is done at the end of the series. I could swap things around a bit and avoid having the intermediate step, but I envision that getting this in all archs will take a bit longer than just signing off on the generic/x86 bits. So probably best to keep the series as it is for now, and work on getting the arch bits verified/fixed/tested. https://git.kernel.dk/cgit/linux-block/log/?h=tif-task_work -- Jens Axboe
