* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] <20210831135035.6443-1-mgurtovoy@nvidia.com> @ 2021-09-01 5:21 ` Christoph Hellwig 2021-09-02 13:45 ` Stefan Hajnoczi 1 sibling, 0 replies; 11+ messages in thread From: Christoph Hellwig @ 2021-09-01 5:21 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, mst, israelr, virtualization, hch, nitzanc, stefanha, oren Looks good, Reviewed-by: Christoph Hellwig <hch@lst.de> _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] <20210831135035.6443-1-mgurtovoy@nvidia.com> 2021-09-01 5:21 ` [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter Christoph Hellwig @ 2021-09-02 13:45 ` Stefan Hajnoczi 2021-09-05 16:02 ` Michael S. Tsirkin 1 sibling, 1 reply; 11+ messages in thread From: Stefan Hajnoczi @ 2021-09-02 13:45 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, mst, israelr, virtualization, hch, nitzanc, oren [-- Attachment #1.1: Type: text/plain, Size: 2048 bytes --] On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > Sometimes a user would like to control the amount of IO queues to be > created for a block device. For example, for limiting the memory > footprint of virtio-blk devices. > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > --- > > changes from v1: > - use param_set_uint_minmax (from Christoph) > - added "Should > 0" to module description > > Note: This commit apply on top of Jens's branch for-5.15/drivers > --- > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 4b49df2dfd23..9332fc4e9b31 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -24,6 +24,22 @@ > /* The maximum number of sg elements that fit into a virtqueue */ > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > +static int virtblk_queue_count_set(const char *val, > + const struct kernel_param *kp) > +{ > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > +} > + > +static const struct kernel_param_ops queue_count_ops = { > + .set = virtblk_queue_count_set, > + .get = param_get_uint, > +}; > + > +static unsigned int num_io_queues; > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > +MODULE_PARM_DESC(num_io_queues, > + "Number of IO virt queues to use for blk device. Should > 0"); > + > static int major; > static DEFINE_IDA(vd_index_ida); > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > if (err) > num_vqs = 1; > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > + num_vqs = min_t(unsigned int, > + min_not_zero(num_io_queues, nr_cpu_ids), > + num_vqs); If you respin, please consider calling them request queues. That's the terminology from the VIRTIO spec and it's nice to keep it consistent. But the purpose of num_io_queues is clear, so: Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 183 bytes --] _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter 2021-09-02 13:45 ` Stefan Hajnoczi @ 2021-09-05 16:02 ` Michael S. Tsirkin [not found] ` <98309fcd-3abe-1f27-fe52-e8fcc58bec13@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-05 16:02 UTC (permalink / raw) To: Stefan Hajnoczi Cc: Max Gurtovoy, linux-block, kvm, israelr, virtualization, hch, nitzanc, axboe, oren On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > Sometimes a user would like to control the amount of IO queues to be > > created for a block device. For example, for limiting the memory > > footprint of virtio-blk devices. > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > --- > > > > changes from v1: > > - use param_set_uint_minmax (from Christoph) > > - added "Should > 0" to module description > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > --- > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > index 4b49df2dfd23..9332fc4e9b31 100644 > > --- a/drivers/block/virtio_blk.c > > +++ b/drivers/block/virtio_blk.c > > @@ -24,6 +24,22 @@ > > /* The maximum number of sg elements that fit into a virtqueue */ > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > +static int virtblk_queue_count_set(const char *val, > > + const struct kernel_param *kp) > > +{ > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > +} > > + > > +static const struct kernel_param_ops queue_count_ops = { > > + .set = virtblk_queue_count_set, > > + .get = param_get_uint, > > +}; > > + > > +static unsigned int num_io_queues; > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > +MODULE_PARM_DESC(num_io_queues, > > + "Number of IO virt queues to use for blk device. Should > 0"); > > + > > static int major; > > static DEFINE_IDA(vd_index_ida); > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > if (err) > > num_vqs = 1; > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > + num_vqs = min_t(unsigned int, > > + min_not_zero(num_io_queues, nr_cpu_ids), > > + num_vqs); > > If you respin, please consider calling them request queues. That's the > terminology from the VIRTIO spec and it's nice to keep it consistent. > But the purpose of num_io_queues is clear, so: > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> I did this: +static unsigned int num_io_request_queues; +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); +MODULE_PARM_DESC(num_io_request_queues, + "Limit number of IO request virt queues to use for each device. 0 for now limit"); _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <98309fcd-3abe-1f27-fe52-e8fcc58bec13@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <98309fcd-3abe-1f27-fe52-e8fcc58bec13@nvidia.com> @ 2021-09-06 11:20 ` Michael S. Tsirkin [not found] ` <1cbbe6e2-1473-8696-565c-518fc1016a1a@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-06 11:20 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > Sometimes a user would like to control the amount of IO queues to be > > > > created for a block device. For example, for limiting the memory > > > > footprint of virtio-blk devices. > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > --- > > > > > > > > changes from v1: > > > > - use param_set_uint_minmax (from Christoph) > > > > - added "Should > 0" to module description > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > --- > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > --- a/drivers/block/virtio_blk.c > > > > +++ b/drivers/block/virtio_blk.c > > > > @@ -24,6 +24,22 @@ > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > +static int virtblk_queue_count_set(const char *val, > > > > + const struct kernel_param *kp) > > > > +{ > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > +} Hmm which tree is this for? > > > > + > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > + .set = virtblk_queue_count_set, > > > > + .get = param_get_uint, > > > > +}; > > > > + > > > > +static unsigned int num_io_queues; > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > +MODULE_PARM_DESC(num_io_queues, > > > > + "Number of IO virt queues to use for blk device. Should > 0"); better: +MODULE_PARM_DESC(num_io_request_queues, + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > + > > > > static int major; > > > > static DEFINE_IDA(vd_index_ida); > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > if (err) > > > > num_vqs = 1; > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > + num_vqs = min_t(unsigned int, > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > + num_vqs); > > > If you respin, please consider calling them request queues. That's the > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > But the purpose of num_io_queues is clear, so: > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > I did this: > > +static unsigned int num_io_request_queues; > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > +MODULE_PARM_DESC(num_io_request_queues, > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > The parameter is writable and can be changed and then new devices might be > probed with new value. > > It can't be zero in the code. we can change param_set_uint_minmax args and > say that 0 says nr_cpus. > > I'm ok with the renaming but I prefer to stick to the description we gave in > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <1cbbe6e2-1473-8696-565c-518fc1016a1a@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <1cbbe6e2-1473-8696-565c-518fc1016a1a@nvidia.com> @ 2021-09-09 13:42 ` Michael S. Tsirkin [not found] ` <456e1704-67e9-aac9-a82a-44fed65dd153@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-09 13:42 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > created for a block device. For example, for limiting the memory > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > --- > > > > > > > > > > > > changes from v1: > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > --- > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > @@ -24,6 +24,22 @@ > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > + const struct kernel_param *kp) > > > > > > +{ > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > +} > > > > Hmm which tree is this for? > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > you can apply it on linus/master as well. > > > > > > > > > > + > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > + .set = virtblk_queue_count_set, > > > > > > + .get = param_get_uint, > > > > > > +}; > > > > > > + > > > > > > +static unsigned int num_io_queues; > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > better: > > > > +MODULE_PARM_DESC(num_io_request_queues, > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > You proposed it and I replied on it bellow. Can't say I understand 100% what you are saying. Want to send a description that does make sense to you but also reflects reality? 0 is the default so "should > 0" besides being ungrammatical does not seem t" reflect what it does ... > > > > > > > > > > > + > > > > > > static int major; > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > if (err) > > > > > > num_vqs = 1; > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > + num_vqs = min_t(unsigned int, > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > + num_vqs); > > > > > If you respin, please consider calling them request queues. That's the > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > I did this: > > > > +static unsigned int num_io_request_queues; > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > The parameter is writable and can be changed and then new devices might be > > > probed with new value. > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > say that 0 says nr_cpus. > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <456e1704-67e9-aac9-a82a-44fed65dd153@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <456e1704-67e9-aac9-a82a-44fed65dd153@nvidia.com> @ 2021-09-09 15:40 ` Michael S. Tsirkin [not found] ` <da61fec0-e90f-0020-c836-c2e58d32be27@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-09 15:40 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > --- > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > --- > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > + const struct kernel_param *kp) > > > > > > > > +{ > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > +} > > > > Hmm which tree is this for? > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > + > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > + .get = param_get_uint, > > > > > > > > +}; > > > > > > > > + > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > > > better: > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > You proposed it and I replied on it bellow. > > > > Can't say I understand 100% what you are saying. Want to send > > a description that does make sense to you but > > also reflects reality? 0 is the default so > > "should > 0" besides being ungrammatical does not seem t" > > reflect what it does ... > > if you "modprobe virtio_blk" the previous behavior will happen. > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > value is 1. > > So your description is not reflecting the code. > > We can do: > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); What's the default value? We should document that. > > > > > > > > > > > > > > + > > > > > > > > static int major; > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > if (err) > > > > > > > > num_vqs = 1; > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > + num_vqs); > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > I did this: > > > > > > +static unsigned int num_io_request_queues; > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > The parameter is writable and can be changed and then new devices might be > > > > > probed with new value. > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > say that 0 says nr_cpus. > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <da61fec0-e90f-0020-c836-c2e58d32be27@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <da61fec0-e90f-0020-c836-c2e58d32be27@nvidia.com> @ 2021-09-09 16:31 ` Michael S. Tsirkin [not found] ` <0cd4ab50-1bb2-3baf-fc00-b2045e8f8eb1@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-09 16:31 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Thu, Sep 09, 2021 at 06:51:56PM +0300, Max Gurtovoy wrote: > > On 9/9/2021 6:40 PM, Michael S. Tsirkin wrote: > > On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > > > --- > > > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > > > + const struct kernel_param *kp) > > > > > > > > > > +{ > > > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > > > +} > > > > > > Hmm which tree is this for? > > > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > > > + .get = param_get_uint, > > > > > > > > > > +}; > > > > > > > > > > + > > > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > better: > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > You proposed it and I replied on it bellow. > > > > Can't say I understand 100% what you are saying. Want to send > > > > a description that does make sense to you but > > > > also reflects reality? 0 is the default so > > > > "should > 0" besides being ungrammatical does not seem t" > > > > reflect what it does ... > > > if you "modprobe virtio_blk" the previous behavior will happen. > > > > > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > > > value is 1. > > > > > > So your description is not reflecting the code. > > > > > > We can do: > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); > > What's the default value? We should document that. > > default value for static global variables is 0. > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to > use for blk device. Minimum value is 1 queue. Default and Maximum value is > equal to the total number of CPUs"); So it says it's the # of cpus but yoiu inspect it with sysfs and it's actually 0. Let's say that's confusing at the least. why not just let users set it to 0 and document that? > > > > > > > > > > > > > + > > > > > > > > > > static int major; > > > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > > > if (err) > > > > > > > > > > num_vqs = 1; > > > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > > > + num_vqs); > > > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > > > I did this: > > > > > > > > +static unsigned int num_io_request_queues; > > > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > The parameter is writable and can be changed and then new devices might be > > > > > > > probed with new value. > > > > > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > > > say that 0 says nr_cpus. > > > > > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <0cd4ab50-1bb2-3baf-fc00-b2045e8f8eb1@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <0cd4ab50-1bb2-3baf-fc00-b2045e8f8eb1@nvidia.com> @ 2021-09-09 22:57 ` Michael S. Tsirkin [not found] ` <9de9a43a-2d3a-493b-516e-4601778b9237@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-09 22:57 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Thu, Sep 09, 2021 at 07:45:42PM +0300, Max Gurtovoy wrote: > > On 9/9/2021 7:31 PM, Michael S. Tsirkin wrote: > > On Thu, Sep 09, 2021 at 06:51:56PM +0300, Max Gurtovoy wrote: > > > On 9/9/2021 6:40 PM, Michael S. Tsirkin wrote: > > > > On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > > > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > > > > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > > > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > > > > > --- > > > > > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > > > > > + const struct kernel_param *kp) > > > > > > > > > > > > +{ > > > > > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > > > > > +} > > > > > > > > Hmm which tree is this for? > > > > > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > > > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > > > > > + .get = param_get_uint, > > > > > > > > > > > > +}; > > > > > > > > > > > > + > > > > > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > > > better: > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > You proposed it and I replied on it bellow. > > > > > > Can't say I understand 100% what you are saying. Want to send > > > > > > a description that does make sense to you but > > > > > > also reflects reality? 0 is the default so > > > > > > "should > 0" besides being ungrammatical does not seem t" > > > > > > reflect what it does ... > > > > > if you "modprobe virtio_blk" the previous behavior will happen. > > > > > > > > > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > > > > > value is 1. > > > > > > > > > > So your description is not reflecting the code. > > > > > > > > > > We can do: > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); > > > > What's the default value? We should document that. > > > default value for static global variables is 0. > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to > > > use for blk device. Minimum value is 1 queue. Default and Maximum value is > > > equal to the total number of CPUs"); > > So it says it's the # of cpus but yoiu inspect it with > > sysfs and it's actually 0. Let's say that's confusing > > at the least. why not just let users set it to 0 > > and document that? > > > Setting it by the user to 0 makes no sense. > > We can say "if not set, the value equals to the total number of CPUs". the value is 0. it seems to mean "no limit". the actual # of queues is then te smaller between # of cpus and # of hardware queues. I see no reason not to allow user to set that especially if it was originally the value then user changed it and is trying to change it back. > The actual value of the created queues can be seen in /sys/block/vda/mq/ as > done today. > > > > > > > > > > > > + > > > > > > > > > > > > static int major; > > > > > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > > > > > if (err) > > > > > > > > > > > > num_vqs = 1; > > > > > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > > > > > + num_vqs); > > > > > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > > > > > I did this: > > > > > > > > > > +static unsigned int num_io_request_queues; > > > > > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > The parameter is writable and can be changed and then new devices might be > > > > > > > > > probed with new value. > > > > > > > > > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > > > > > say that 0 says nr_cpus. > > > > > > > > > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <9de9a43a-2d3a-493b-516e-4601778b9237@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <9de9a43a-2d3a-493b-516e-4601778b9237@nvidia.com> @ 2021-09-12 9:07 ` Michael S. Tsirkin [not found] ` <f58f955e-ef27-fba1-7417-8d37a175e872@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-12 9:07 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Sat, Sep 11, 2021 at 03:56:45PM +0300, Max Gurtovoy wrote: > > On 9/10/2021 1:57 AM, Michael S. Tsirkin wrote: > > On Thu, Sep 09, 2021 at 07:45:42PM +0300, Max Gurtovoy wrote: > > > On 9/9/2021 7:31 PM, Michael S. Tsirkin wrote: > > > > On Thu, Sep 09, 2021 at 06:51:56PM +0300, Max Gurtovoy wrote: > > > > > On 9/9/2021 6:40 PM, Michael S. Tsirkin wrote: > > > > > > On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > > > > > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > > > > > > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > > > > > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > > > > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > > > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > > > > > > > + const struct kernel_param *kp) > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > > > > > > > +} > > > > > > > > > > Hmm which tree is this for? > > > > > > > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > > > > > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > > > > > > > + .get = param_get_uint, > > > > > > > > > > > > > > +}; > > > > > > > > > > > > > > + > > > > > > > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > > > > > better: > > > > > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > You proposed it and I replied on it bellow. > > > > > > > > Can't say I understand 100% what you are saying. Want to send > > > > > > > > a description that does make sense to you but > > > > > > > > also reflects reality? 0 is the default so > > > > > > > > "should > 0" besides being ungrammatical does not seem t" > > > > > > > > reflect what it does ... > > > > > > > if you "modprobe virtio_blk" the previous behavior will happen. > > > > > > > > > > > > > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > > > > > > > value is 1. > > > > > > > > > > > > > > So your description is not reflecting the code. > > > > > > > > > > > > > > We can do: > > > > > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); > > > > > > What's the default value? We should document that. > > > > > default value for static global variables is 0. > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to > > > > > use for blk device. Minimum value is 1 queue. Default and Maximum value is > > > > > equal to the total number of CPUs"); > > > > So it says it's the # of cpus but yoiu inspect it with > > > > sysfs and it's actually 0. Let's say that's confusing > > > > at the least. why not just let users set it to 0 > > > > and document that? > > > > > > > Setting it by the user to 0 makes no sense. > > > > > > We can say "if not set, the value equals to the total number of CPUs". > > the value is 0. it seems to mean "no limit". the actual # of queues is > > then te smaller between # of cpus and # of hardware queues. > > I see no reason not to allow user to set that especially if > > it was originally the value then user changed it > > and is trying to change it back. > > I fine with that. > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. 0 value means no limitation"); > OK and the second distinction is that it's a limit on the number, not the actual number. It's never more than what's provided by the hypervisor. > > > > > The actual value of the created queues can be seen in /sys/block/vda/mq/ as > > > done today. > > > > > > > > > > > > > > + > > > > > > > > > > > > > > static int major; > > > > > > > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > > > > > > > if (err) > > > > > > > > > > > > > > num_vqs = 1; > > > > > > > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > > > > > > > + num_vqs); > > > > > > > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > > > > > > > I did this: > > > > > > > > > > > > +static unsigned int num_io_request_queues; > > > > > > > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > > > The parameter is writable and can be changed and then new devices might be > > > > > > > > > > > probed with new value. > > > > > > > > > > > > > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > > > > > > > say that 0 says nr_cpus. > > > > > > > > > > > > > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > > > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <f58f955e-ef27-fba1-7417-8d37a175e872@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <f58f955e-ef27-fba1-7417-8d37a175e872@nvidia.com> @ 2021-09-12 9:50 ` Michael S. Tsirkin [not found] ` <eb7c3e87-d71e-9f86-c5c6-6a8b9474f78a@nvidia.com> 0 siblings, 1 reply; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-12 9:50 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Sun, Sep 12, 2021 at 12:37:26PM +0300, Max Gurtovoy wrote: > > On 9/12/2021 12:07 PM, Michael S. Tsirkin wrote: > > On Sat, Sep 11, 2021 at 03:56:45PM +0300, Max Gurtovoy wrote: > > > On 9/10/2021 1:57 AM, Michael S. Tsirkin wrote: > > > > On Thu, Sep 09, 2021 at 07:45:42PM +0300, Max Gurtovoy wrote: > > > > > On 9/9/2021 7:31 PM, Michael S. Tsirkin wrote: > > > > > > On Thu, Sep 09, 2021 at 06:51:56PM +0300, Max Gurtovoy wrote: > > > > > > > On 9/9/2021 6:40 PM, Michael S. Tsirkin wrote: > > > > > > > > On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > > > > > > > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > > > > > > > > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > > > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > > > > > > > > > + const struct kernel_param *kp) > > > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > > > > > > > > > +} > > > > > > > > > > > > Hmm which tree is this for? > > > > > > > > > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > > > > > > > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > > > > > > > > > + .get = param_get_uint, > > > > > > > > > > > > > > > > +}; > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > > > > > > > better: > > > > > > > > > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > > > You proposed it and I replied on it bellow. > > > > > > > > > > Can't say I understand 100% what you are saying. Want to send > > > > > > > > > > a description that does make sense to you but > > > > > > > > > > also reflects reality? 0 is the default so > > > > > > > > > > "should > 0" besides being ungrammatical does not seem t" > > > > > > > > > > reflect what it does ... > > > > > > > > > if you "modprobe virtio_blk" the previous behavior will happen. > > > > > > > > > > > > > > > > > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > > > > > > > > > value is 1. > > > > > > > > > > > > > > > > > > So your description is not reflecting the code. > > > > > > > > > > > > > > > > > > We can do: > > > > > > > > > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); > > > > > > > > What's the default value? We should document that. > > > > > > > default value for static global variables is 0. > > > > > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to > > > > > > > use for blk device. Minimum value is 1 queue. Default and Maximum value is > > > > > > > equal to the total number of CPUs"); > > > > > > So it says it's the # of cpus but yoiu inspect it with > > > > > > sysfs and it's actually 0. Let's say that's confusing > > > > > > at the least. why not just let users set it to 0 > > > > > > and document that? > > > > > > > > > > > Setting it by the user to 0 makes no sense. > > > > > > > > > > We can say "if not set, the value equals to the total number of CPUs". > > > > the value is 0. it seems to mean "no limit". the actual # of queues is > > > > then te smaller between # of cpus and # of hardware queues. > > > > I see no reason not to allow user to set that especially if > > > > it was originally the value then user changed it > > > > and is trying to change it back. > > > I fine with that. > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. 0 value means no limitation"); > > > > > OK and the second distinction is that it's a limit on the > > number, not the actual number. It's never more than what's provided > > by the hypervisor. > > MODULE_PARM_DESC(num_io_request_queues, "Maximal number of request virt queues to use for blk device. 0 value means no limitation"); > > is that ok ? Looks ok. And then do we need to limit this to nr_cpu_ids? Setting a value that's too high seems harmless ... > > > > > The actual value of the created queues can be seen in /sys/block/vda/mq/ as > > > > > done today. > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > static int major; > > > > > > > > > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > > > > > > > > > if (err) > > > > > > > > > > > > > > > > num_vqs = 1; > > > > > > > > > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > > > > > > > > > + num_vqs); > > > > > > > > > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > > > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > > > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > > > > > > > > > I did this: > > > > > > > > > > > > > > +static unsigned int num_io_request_queues; > > > > > > > > > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > > > > > The parameter is writable and can be changed and then new devices might be > > > > > > > > > > > > > probed with new value. > > > > > > > > > > > > > > > > > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > > > > > > > > > say that 0 says nr_cpus. > > > > > > > > > > > > > > > > > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > > > > > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
[parent not found: <eb7c3e87-d71e-9f86-c5c6-6a8b9474f78a@nvidia.com>]
* Re: [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter [not found] ` <eb7c3e87-d71e-9f86-c5c6-6a8b9474f78a@nvidia.com> @ 2021-09-12 11:45 ` Michael S. Tsirkin 0 siblings, 0 replies; 11+ messages in thread From: Michael S. Tsirkin @ 2021-09-12 11:45 UTC (permalink / raw) To: Max Gurtovoy Cc: axboe, linux-block, kvm, israelr, virtualization, hch, nitzanc, Stefan Hajnoczi, oren On Sun, Sep 12, 2021 at 01:33:13PM +0300, Max Gurtovoy wrote: > > On 9/12/2021 12:50 PM, Michael S. Tsirkin wrote: > > On Sun, Sep 12, 2021 at 12:37:26PM +0300, Max Gurtovoy wrote: > > > On 9/12/2021 12:07 PM, Michael S. Tsirkin wrote: > > > > On Sat, Sep 11, 2021 at 03:56:45PM +0300, Max Gurtovoy wrote: > > > > > On 9/10/2021 1:57 AM, Michael S. Tsirkin wrote: > > > > > > On Thu, Sep 09, 2021 at 07:45:42PM +0300, Max Gurtovoy wrote: > > > > > > > On 9/9/2021 7:31 PM, Michael S. Tsirkin wrote: > > > > > > > > On Thu, Sep 09, 2021 at 06:51:56PM +0300, Max Gurtovoy wrote: > > > > > > > > > On 9/9/2021 6:40 PM, Michael S. Tsirkin wrote: > > > > > > > > > > On Thu, Sep 09, 2021 at 06:37:37PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > On 9/9/2021 4:42 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > On Mon, Sep 06, 2021 at 02:59:40PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > On 9/6/2021 2:20 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > > > On Mon, Sep 06, 2021 at 01:31:32AM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > > > On 9/5/2021 7:02 PM, Michael S. Tsirkin wrote: > > > > > > > > > > > > > > > > On Thu, Sep 02, 2021 at 02:45:52PM +0100, Stefan Hajnoczi wrote: > > > > > > > > > > > > > > > > > On Tue, Aug 31, 2021 at 04:50:35PM +0300, Max Gurtovoy wrote: > > > > > > > > > > > > > > > > > > Sometimes a user would like to control the amount of IO queues to be > > > > > > > > > > > > > > > > > > created for a block device. For example, for limiting the memory > > > > > > > > > > > > > > > > > > footprint of virtio-blk devices. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > changes from v1: > > > > > > > > > > > > > > > > > > - use param_set_uint_minmax (from Christoph) > > > > > > > > > > > > > > > > > > - added "Should > 0" to module description > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Note: This commit apply on top of Jens's branch for-5.15/drivers > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > drivers/block/virtio_blk.c | 20 +++++++++++++++++++- > > > > > > > > > > > > > > > > > > 1 file changed, 19 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > > > index 4b49df2dfd23..9332fc4e9b31 100644 > > > > > > > > > > > > > > > > > > --- a/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > > > +++ b/drivers/block/virtio_blk.c > > > > > > > > > > > > > > > > > > @@ -24,6 +24,22 @@ > > > > > > > > > > > > > > > > > > /* The maximum number of sg elements that fit into a virtqueue */ > > > > > > > > > > > > > > > > > > #define VIRTIO_BLK_MAX_SG_ELEMS 32768 > > > > > > > > > > > > > > > > > > +static int virtblk_queue_count_set(const char *val, > > > > > > > > > > > > > > > > > > + const struct kernel_param *kp) > > > > > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > > > > > + return param_set_uint_minmax(val, kp, 1, nr_cpu_ids); > > > > > > > > > > > > > > > > > > +} > > > > > > > > > > > > > > Hmm which tree is this for? > > > > > > > > > > > > > I've mentioned in the note that it apply on branch for-5.15/drivers. But now > > > > > > > > > > > > > you can apply it on linus/master as well. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > > > +static const struct kernel_param_ops queue_count_ops = { > > > > > > > > > > > > > > > > > > + .set = virtblk_queue_count_set, > > > > > > > > > > > > > > > > > > + .get = param_get_uint, > > > > > > > > > > > > > > > > > > +}; > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > > > +static unsigned int num_io_queues; > > > > > > > > > > > > > > > > > > +module_param_cb(num_io_queues, &queue_count_ops, &num_io_queues, 0644); > > > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_queues, > > > > > > > > > > > > > > > > > > + "Number of IO virt queues to use for blk device. Should > 0"); > > > > > > > > > > > > > > better: > > > > > > > > > > > > > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > > > > > You proposed it and I replied on it bellow. > > > > > > > > > > > > Can't say I understand 100% what you are saying. Want to send > > > > > > > > > > > > a description that does make sense to you but > > > > > > > > > > > > also reflects reality? 0 is the default so > > > > > > > > > > > > "should > 0" besides being ungrammatical does not seem t" > > > > > > > > > > > > reflect what it does ... > > > > > > > > > > > if you "modprobe virtio_blk" the previous behavior will happen. > > > > > > > > > > > > > > > > > > > > > > You can't "modprobe virtio_blk num_io_request_queues=0" since the minimal > > > > > > > > > > > value is 1. > > > > > > > > > > > > > > > > > > > > > > So your description is not reflecting the code. > > > > > > > > > > > > > > > > > > > > > > We can do: > > > > > > > > > > > > > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. Minimum value is 1 queue"); > > > > > > > > > > What's the default value? We should document that. > > > > > > > > > default value for static global variables is 0. > > > > > > > > > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to > > > > > > > > > use for blk device. Minimum value is 1 queue. Default and Maximum value is > > > > > > > > > equal to the total number of CPUs"); > > > > > > > > So it says it's the # of cpus but yoiu inspect it with > > > > > > > > sysfs and it's actually 0. Let's say that's confusing > > > > > > > > at the least. why not just let users set it to 0 > > > > > > > > and document that? > > > > > > > > > > > > > > > Setting it by the user to 0 makes no sense. > > > > > > > > > > > > > > We can say "if not set, the value equals to the total number of CPUs". > > > > > > the value is 0. it seems to mean "no limit". the actual # of queues is > > > > > > then te smaller between # of cpus and # of hardware queues. > > > > > > I see no reason not to allow user to set that especially if > > > > > > it was originally the value then user changed it > > > > > > and is trying to change it back. > > > > > I fine with that. > > > > > > > > > > MODULE_PARM_DESC(num_io_request_queues, "Number of request virt queues to use for blk device. 0 value means no limitation"); > > > > > > > > > OK and the second distinction is that it's a limit on the > > > > number, not the actual number. It's never more than what's provided > > > > by the hypervisor. > > > MODULE_PARM_DESC(num_io_request_queues, "Maximal number of request virt queues to use for blk device. 0 value means no limitation"); > > > > > > is that ok ? > > > > Looks ok. And then do we need to limit this to nr_cpu_ids? > > Setting a value that's too high seems harmless ... > > why would you want that ? So one can write a script that keeps working even when hypervisor changes the # of CPU IDs. It's also consistent with other parameters, e.g.: clocksource.verify_n_cpus= [KNL] Limit the number of CPUs checked for clocksources marked with CLOCK_SOURCE_VERIFY_PERCPU that are marked unstable due to excessive skew. A negative value says to check all CPUs, while zero says not to check any. Values larger than nr_cpu_ids are silently truncated to nr_cpu_ids. ^^^^^^^^^^^^ The actual CPUs are chosen randomly, with no replacement if the same CPU is chosen twice. > > > > > > > > > > The actual value of the created queues can be seen in /sys/block/vda/mq/ as > > > > > > > done today. > > > > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > > > > static int major; > > > > > > > > > > > > > > > > > > static DEFINE_IDA(vd_index_ida); > > > > > > > > > > > > > > > > > > @@ -501,7 +517,9 @@ static int init_vq(struct virtio_blk *vblk) > > > > > > > > > > > > > > > > > > if (err) > > > > > > > > > > > > > > > > > > num_vqs = 1; > > > > > > > > > > > > > > > > > > - num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); > > > > > > > > > > > > > > > > > > + num_vqs = min_t(unsigned int, > > > > > > > > > > > > > > > > > > + min_not_zero(num_io_queues, nr_cpu_ids), > > > > > > > > > > > > > > > > > > + num_vqs); > > > > > > > > > > > > > > > > > If you respin, please consider calling them request queues. That's the > > > > > > > > > > > > > > > > > terminology from the VIRTIO spec and it's nice to keep it consistent. > > > > > > > > > > > > > > > > > But the purpose of num_io_queues is clear, so: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > > > > > > > > > > > > > > > I did this: > > > > > > > > > > > > > > > > +static unsigned int num_io_request_queues; > > > > > > > > > > > > > > > > +module_param_cb(num_io_request_queues, &queue_count_ops, &num_io_request_queues, 0644); > > > > > > > > > > > > > > > > +MODULE_PARM_DESC(num_io_request_queues, > > > > > > > > > > > > > > > > + "Limit number of IO request virt queues to use for each device. 0 for now limit"); > > > > > > > > > > > > > > > The parameter is writable and can be changed and then new devices might be > > > > > > > > > > > > > > > probed with new value. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > It can't be zero in the code. we can change param_set_uint_minmax args and > > > > > > > > > > > > > > > say that 0 says nr_cpus. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I'm ok with the renaming but I prefer to stick to the description we gave in > > > > > > > > > > > > > > > V3 of this patch (and maybe enable value of 0 as mentioned above). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2021-09-12 11:46 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <20210831135035.6443-1-mgurtovoy@nvidia.com>
2021-09-01 5:21 ` [PATCH v2 1/1] virtio-blk: add num_io_queues module parameter Christoph Hellwig
2021-09-02 13:45 ` Stefan Hajnoczi
2021-09-05 16:02 ` Michael S. Tsirkin
[not found] ` <98309fcd-3abe-1f27-fe52-e8fcc58bec13@nvidia.com>
2021-09-06 11:20 ` Michael S. Tsirkin
[not found] ` <1cbbe6e2-1473-8696-565c-518fc1016a1a@nvidia.com>
2021-09-09 13:42 ` Michael S. Tsirkin
[not found] ` <456e1704-67e9-aac9-a82a-44fed65dd153@nvidia.com>
2021-09-09 15:40 ` Michael S. Tsirkin
[not found] ` <da61fec0-e90f-0020-c836-c2e58d32be27@nvidia.com>
2021-09-09 16:31 ` Michael S. Tsirkin
[not found] ` <0cd4ab50-1bb2-3baf-fc00-b2045e8f8eb1@nvidia.com>
2021-09-09 22:57 ` Michael S. Tsirkin
[not found] ` <9de9a43a-2d3a-493b-516e-4601778b9237@nvidia.com>
2021-09-12 9:07 ` Michael S. Tsirkin
[not found] ` <f58f955e-ef27-fba1-7417-8d37a175e872@nvidia.com>
2021-09-12 9:50 ` Michael S. Tsirkin
[not found] ` <eb7c3e87-d71e-9f86-c5c6-6a8b9474f78a@nvidia.com>
2021-09-12 11:45 ` Michael S. Tsirkin
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