On 07.08.24 15:25, Eugenio Perez Martin wrote: > On Fri, Aug 2, 2024 at 9:24 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote: >> >> This series parallelizes the mlx5_vdpa device suspend and resume >> operations through the firmware async API. The purpose is to reduce live >> migration downtime. >> >> The series starts with changing the VQ suspend and resume commands >> to the async API. After that, the switch is made to issue multiple >> commands of the same type in parallel. >> > > There is a missed opportunity processing the CVQ MQ command here, > isn't it? It can be applied on top in another series for sure. > Initially I considered that it would complicate the code too much in change_num_qps(). But in the current state of the patches it's doable. Will send a V2 with an extra patch for this. >> Finally, a bonus improvement is thrown in: keep the notifierd enabled >> during suspend but make it a NOP. Upon resume make sure that the link >> state is forwarded. This shaves around 30ms per device constant time. >> >> For 1 vDPA device x 32 VQs (16 VQPs), on a large VM (256 GB RAM, 32 CPUs >> x 2 threads per core), the improvements are: >> >> +-------------------+--------+--------+-----------+ >> | operation | Before | After | Reduction | >> |-------------------+--------+--------+-----------| >> | mlx5_vdpa_suspend | 37 ms | 2.5 ms | 14x | >> | mlx5_vdpa_resume | 16 ms | 5 ms | 3x | >> +-------------------+--------+--------+-----------+ >> > > Looks great :). > > Apart from the nitpick, > > Acked-by: Eugenio Pérez <eperezma@xxxxxxxxxx> > > For the vhost part. Thanks! > > Thanks! > >> Note for the maintainers: >> The first patch contains changes for mlx5_core. This must be applied >> into the mlx5-vhost tree [0] first. Once this patch is applied on >> mlx5-vhost, the change has to be pulled from mlx5-vdpa into the vhost >> tree and only then the remaining patches can be applied. >> >> [0] https://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux.git/log/?h=mlx5-vhost >> >> Dragos Tatulea (7): >> net/mlx5: Support throttled commands from async API >> vdpa/mlx5: Introduce error logging function >> vdpa/mlx5: Use async API for vq query command >> vdpa/mlx5: Use async API for vq modify commands >> vdpa/mlx5: Parallelize device suspend >> vdpa/mlx5: Parallelize device resume >> vdpa/mlx5: Keep notifiers during suspend but ignore >> >> drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 21 +- >> drivers/vdpa/mlx5/core/mlx5_vdpa.h | 7 + >> drivers/vdpa/mlx5/net/mlx5_vnet.c | 435 +++++++++++++----- >> 3 files changed, 333 insertions(+), 130 deletions(-) >> >> -- >> 2.45.2 >> >
