search for: nr_map

When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are use by virtio-blk/virtio-scsi, as they both have (tag_set->nr_maps == 1), they can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' sp...

...more queues when there is limited number of vectors. Another use case we may classify queues as hight priority or low priority as mentioned by Cornelia. For virtio-blk, we may extend virtio-blk based on this patch set to enable something similar to write_queues/poll_queues in nvme, when (set->nr_maps != 1). Yet, the question I am asking in this email thread is for a difference scenario. The issue is not we are not having enough vectors (although this is why only 1 vector is allocated for all virtio-blk queues). As so far virtio-blk has (set->nr_maps == 1), block layer would limit the num...

...more queues when there is limited number of vectors. Another use case we may classify queues as hight priority or low priority as mentioned by Cornelia. For virtio-blk, we may extend virtio-blk based on this patch set to enable something similar to write_queues/poll_queues in nvme, when (set->nr_maps != 1). Yet, the question I am asking in this email thread is for a difference scenario. The issue is not we are not having enough vectors (although this is why only 1 vector is allocated for all virtio-blk queues). As so far virtio-blk has (set->nr_maps == 1), block layer would limit the num...

...+ +/* Return true if two mappings overlap in the request range. */ +static int +mappings_overlap (const struct mapping *m1, const struct mapping *m2) +{ + return m1->rq_end >= m2->rq_start && m1->rq_start <= m2->rq_end; +} + +void +map_init (struct map *map) +{ + map->nr_map = 0; + map->map = NULL; +} + +void +map_free (struct map *map) +{ + if (!map) return; + free (map->map); + map_init (map); +} + +/* Return the highest address in the map+1. */ +int64_t +map_size (struct map *map) +{ + if (map->nr_map == 0) + return 0; + else + return map->ma...

...pecific: Have some low-traffic status queues > share a vector, and provide an individual vector for high-traffic > queues. Would need some device<->transport interface, obviously. > This sounds a little bit similar to multiple hctx maps? So far, as virtio-blk only supports set->nr_maps = 1, no matter how many hw queues are assigned for virtio-blk, blk_mq_alloc_tag_set() would use at most nr_cpu_ids hw queues. 2981 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) ... ... 3021 /* 3022 * There is no use for more h/w queues than cpus if we just have 3023...

...pecific: Have some low-traffic status queues > share a vector, and provide an individual vector for high-traffic > queues. Would need some device<->transport interface, obviously. > This sounds a little bit similar to multiple hctx maps? So far, as virtio-blk only supports set->nr_maps = 1, no matter how many hw queues are assigned for virtio-blk, blk_mq_alloc_tag_set() would use at most nr_cpu_ids hw queues. 2981 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) ... ... 3021 /* 3022 * There is no use for more h/w queues than cpus if we just have 3023...

...imited number of vectors. > > Another use case we may classify queues as hight priority or low priority as > mentioned by Cornelia. > > For virtio-blk, we may extend virtio-blk based on this patch set to enable > something similar to write_queues/poll_queues in nvme, when (set->nr_maps != 1). > > > Yet, the question I am asking in this email thread is for a difference scenario. > > The issue is not we are not having enough vectors (although this is why only 1 > vector is allocated for all virtio-blk queues). As so far virtio-blk has > (set->nr_maps == 1),...

..._limit(top_of_ram, "MTRRs do not cover all of memory."); } +/* This function relies on the passed in e820->map[] being sorted. */ +int __init e820_add_range( + struct e820map *e820, uint64_t s, uint64_t e, uint32_t type) +{ + unsigned int i; + + for ( i = 0; i < e820->nr_map; ++i ) + { + uint64_t rs = e820->map[i].addr; + uint64_t re = rs + e820->map[i].size; + + if ( rs == e && e820->map[i].type == type ) + { + e820->map[i].addr = s; + return 1; + } + + if ( re == s && e820-...

On Fri, 15 Mar 2019 12:50:11 +0800 Jason Wang <jasowang at redhat.com> wrote: > Or something like I proposed several years ago? > https://do-db2.lkml.org/lkml/2014/12/25/169 > > Btw, for virtio-net, I think we actually want to go for having a maximum > number of supported queues like what hardware did. This would be useful > for e.g cpu hotplug or XDP (requires per cpu

On Fri, 15 Mar 2019 12:50:11 +0800 Jason Wang <jasowang at redhat.com> wrote: > Or something like I proposed several years ago? > https://do-db2.lkml.org/lkml/2014/12/25/169 > > Btw, for virtio-net, I think we actually want to go for having a maximum > number of supported queues like what hardware did. This would be useful > for e.g cpu hotplug or XDP (requires per cpu

...that important? Anyway, the patch itself: diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 9c38bd1..f831568 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -229,7 +229,7 @@ char * __init xen_memory_setup(void) memcpy(map_raw, map, sizeof(map)); e820.nr_map = 0; - xen_extra_mem_start = mem_end; + xen_extra_mem_start = mem_end < (1UL<<32) ? (1UL<<32) : mem_end; for (i = 0; i < memmap.nr_entries; i++) { unsigned long long end; "(1UL<<32)" will overflow on a 32 bit kernel. Oh hang on...

...queues > > share a vector, and provide an individual vector for high-traffic > > queues. Would need some device<->transport interface, obviously. > > > > This sounds a little bit similar to multiple hctx maps? > > So far, as virtio-blk only supports set->nr_maps = 1, no matter how many hw > queues are assigned for virtio-blk, blk_mq_alloc_tag_set() would use at most > nr_cpu_ids hw queues. > > 2981 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) > ... ... > 3021 /* > 3022 * There is no use for more h/w queues th...

...raffic status queues >> share a vector, and provide an individual vector for high-traffic >> queues. Would need some device<->transport interface, obviously. >> > This sounds a little bit similar to multiple hctx maps? > > So far, as virtio-blk only supports set->nr_maps = 1, no matter how many hw > queues are assigned for virtio-blk, blk_mq_alloc_tag_set() would use at most > nr_cpu_ids hw queues. > > 2981 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) > ... ... > 3021 /* > 3022 * There is no use for more h/w queues tha...

When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' specified by qemu is mo...

When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-scsi, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num_queues' specified by qemu is m...

From: Dongli Zhang <dongli.zhang at oracle.com> [ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ] When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' specified by qemu is mo...

From: Dongli Zhang <dongli.zhang at oracle.com> [ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ] When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' specified by qemu is mo...

From: Dongli Zhang <dongli.zhang at oracle.com> [ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ] When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' specified by qemu is mo...

From: Dongli Zhang <dongli.zhang at oracle.com> [ Upstream commit bf348f9b78d413e75bb079462751a1d86b6de36c ] When tag_set->nr_maps is 1, the block layer limits the number of hw queues by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues. In addition, specifically for pci scenario, when the 'num-queues' specified by qemu is mo...

This patch series proposes two new filters. * truncate: This can truncate, extend, round up or round down the size of a plugin/device. A typical usage is to fix the qemu problem that it can only handle devices which are a multiple of 512-bytes: nbdkit --filter=truncate random size=500 round-up=512 This will serve a virtual device with size 512 bytes. Reading from the last 12 bytes will