Messages in this thread | | | Date | Tue, 13 Mar 2018 15:45:46 -0400 | From | Pavel Tatashin <> | Subject | Re: [v5 1/2] mm: disable interrupts while initializing deferred pages |
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> > > > We must remove cond_resched() because we can't sleep anymore. They were > > added to fight NMI timeouts, so I will replace them with > > touch_nmi_watchdog() in a follow-up fix. > > This makes no sense. Any code section where we can add cond_resched() > was never subject to NMI timeouts because that code cannot be running with > disabled interrupts. >
Hi Andrew,
I was talking about this patch:
9b6e63cbf85b89b2dbffa4955dbf2df8250e5375 mm, page_alloc: add scheduling point to memmap_init_zone
Which adds cond_resched() to memmap_init_zone() to avoid NMI timeouts.
memmap_init_zone() is used both, early in boot, when non-deferred struct pages are initialized, but also may be used later, during memory hotplug.
As I understand, the later case could cause the timeout on non-preemptible kernels.
My understanding, is that the same logic was used here when cond_resched()s were added.
Please correct me if I am wrong.
Thank you, Pavel
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