Messages in this thread | | | From | Ard Biesheuvel <> | Date | Tue, 17 Oct 2023 09:42:13 +0200 | Subject | Re: [PATCHv2] efi/unaccepted: Fix soft lockups caused by parallel memory acceptance |
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On Mon, 16 Oct 2023 at 23:39, Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > > On Mon, Oct 16, 2023 at 06:55:41PM +0100, Matthew Wilcox wrote: > > On Mon, Oct 16, 2023 at 07:31:22PM +0300, Kirill A. Shutemov wrote: > > > v2: > > > - Fix deadlock (Vlastimil); > > > - Fix comments (Vlastimil); > > > - s/cond_resched()/cpu_relax()/ -- cond_resched() cannot be called > > > from atomic context; > > > > Isn't there an implicit cpu_relax() while we're spinning? Does this > > really accomplish anything? > > You are right. It is useless. I will drop it in v3. >
I can drop that bit when applying the patch.
One question I have is whether the sequence
spin_lock_irqsave(&unaccepted_memory_lock, flags); ... spin_unlock(&unaccepted_memory_lock); arch_accept_memory(phys_start, phys_end); spin_lock(&unaccepted_memory_lock); ... spin_unlock_irqrestore(&unaccepted_memory_lock, flags);
is considered sound and is supported by all architectures?
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