Re: [GIT PULL] percpu changes for v4.21-rc1

From: Dennis Zhou
Date: Fri Dec 28 2018 - 11:31:47 EST


On Thu, Dec 27, 2018 at 11:04:32AM -0600, Dennis Zhou wrote:
> Hi Linus,
>
> Michael Cree noted generic UP Alpha has been broken since v3.18. This is
> a small fix for locking in UP percpu code that fixes the issue.
>
> Thanks,
> Dennis
>
> The following changes since commit 7566ec393f4161572ba6f11ad5171fd5d59b0fbd:
>
> Linux 4.20-rc7 (2018-12-16 15:46:55 -0800)
>
> are available in the Git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu.git for-4.21
>
> for you to fetch changes up to 6ab7d47bcbf0144a8cb81536c2cead4cde18acfe:
>
> percpu: convert spin_lock_irq to spin_lock_irqsave. (2018-12-18 09:04:08 -0800)
>
> ----------------------------------------------------------------
> Dennis Zhou (1):
> percpu: convert spin_lock_irq to spin_lock_irqsave.
>
> mm/percpu-km.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/percpu-km.c b/mm/percpu-km.c
> index 38de70ab1a0d..0f643dc2dc65 100644
> --- a/mm/percpu-km.c
> +++ b/mm/percpu-km.c
> @@ -50,6 +50,7 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
> const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
> struct pcpu_chunk *chunk;
> struct page *pages;
> + unsigned long flags;
> int i;
>
> chunk = pcpu_alloc_chunk(gfp);
> @@ -68,9 +69,9 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp)
> chunk->data = pages;
> chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];
>
> - spin_lock_irq(&pcpu_lock);
> + spin_lock_irqsave(&pcpu_lock, flags);
> pcpu_chunk_populated(chunk, 0, nr_pages, false);
> - spin_unlock_irq(&pcpu_lock);
> + spin_unlock_irqrestore(&pcpu_lock, flags);
>
> pcpu_stats_chunk_alloc();
> trace_percpu_create_chunk(chunk->base_addr);
>

Sigh, I missed +linux-kernel..

Thanks,
Dennis