lkml.org 
[lkml]   [2020]   [Apr]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH 05/11] hv_utils: Always execute the fcopy and vss callbacks in a tasklet
Date
From: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Sent: Sunday, April 5, 2020 5:15 PM
>
> The fcopy and vss callback functions could be running in a tasklet
> at the same time they are called in hv_poll_channel(). Current code
> serializes the invocations of these functions, and their accesses to
> the channel ring buffer, by sending an IPI to the CPU that is allowed
> to access the ring buffer, cf. hv_poll_channel(). This IPI mechanism
> becomes infeasible if we allow changing the CPU that a channel will
> interrupt. Instead modify the callback wrappers to always execute
> the fcopy and vss callbacks in a tasklet, thus mirroring the solution
> for the kvp callback functions adopted since commit a3ade8cc474d8
> ("HV: properly delay KVP packets when negotiation is in progress").
> This will ensure that the callback function can't run on two CPUs at
> the same time.
>
> Suggested-by: Michael Kelley <mikelley@microsoft.com>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
> ---
> drivers/hv/hv_fcopy.c | 2 +-
> drivers/hv/hv_snapshot.c | 2 +-
> drivers/hv/hyperv_vmbus.h | 7 +------
> 3 files changed, 3 insertions(+), 8 deletions(-)
>

Reviewed-by: Michael Kelley <mikelley@microsoft.com>

\
 
 \ /
  Last update: 2020-04-10 21:27    [W:0.197 / U:0.860 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site