Issuing write requests to a fabric

Patent metadata

Field	Value
Publication number	US-10691348-B2
Application number	US-201916274189-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Mar 8, 2017
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A system comprises a processor, a memory fabric, and a fabric bridge coupled to the memory fabric and the processor. The fabric bridge may receive, from the processor a first eviction request comprising first eviction data, transmit, to the processor, a message indicating the fabric bridge has accepted the first eviction request, transmit a first write comprising the first eviction data to the fabric, receive, from the processor, a second eviction request comprising second eviction data, and transmit a second write comprising the second eviction data to the fabric. Responsive to transmitting the second write request, the fabric bridge may transmit, to the processor, a message indicating the fabric bridge accepted the second eviction request, determine that the first write and the second write have persisted, and transmit, to the processor, a notification to the processor responsive to determining that the first write and the second write have persisted.

First claim

The invention claimed is:

1. A system comprising:
a processor;
a memory fabric; and
a fabric bridge, the fabric bridge coupled to the memory fabric and the processor, the fabric bridge to:
receive, from the processor a first eviction request comprising first eviction data;
transmit, to the processor, a message indicating the fabric bridge has accepted the first eviction request;
transmit a first write comprising the first eviction data to the fabric;
receive, from the processor, a second eviction request comprising second eviction data;
transmit a second write comprising the second eviction data to the fabric; and
responsive to transmitting the second write request:
transmit; to the processor, a message indicating the fabric bridge accepted the second eviction request;

determine that the first write and the second write have persisted; and
transmit, to the processor, a notification to the processor responsive to determining that the first write and the second write have persisted;

wherein to determine whether the first write and the second write have persisted, the fabric bridge to:
store, in a counter, a number of pending writes issued to the fabric;
decrement the counter responsive to receiving an indication via the fabric that one of the pending writes has persisted; and

transmit the notification to the processor indicating that the first write and the second write have persisted responsive to the counter being equal to zero;
wherein the fabric bridge is to:
responsive to receiving a request to read a status register of the fabric bridge:
assign the first write and the second write to an epoch;
track a first number of pending writes in the first epoch with a first counter;

receive a third eviction request comprising third eviction data;
transmit a third write request comprising the third eviction data to the fabric;
receive a second read request for a status register of the fabric bridge;
responsive to receiving the second read request:
assign the third write request to a second epoch; and

track a second number of pending writes in the second epoch with a second counter.

2. The system of claim 1 , the fabric bridge to:
receive, from the fabric bridge, a request to read a register of the fabric bridge;
responsive to receiving the read request and responsive to determining that the first write and the second write have persisted:
transmit the notification, by the fabric bridge and to the processor, that the first write and the second write have persisted.

3. The system of claim 1 , the fabric bridge to:
receive an acknowledgement of a write from the fabric, the acknowledgement comprising an identifier;
determining an epoch for the acknowledge write based on the identifier; and
determine whether the first write and the second write have persisted based on the determined epoch.

4. The system of claim 1 , wherein the fabric bridge to:
receive an acknowledgement, via the fabric, of the first write;
responsive to receiving the acknowledgement of the first write:
update a counter indicating a number of pending writes of an epoch of the first write and the second write.

5. The system of claim 1 , wherein the fabric bridge to:
determine whether the first write, and the second write, have a same epoch; and
update a first counter indicating a number of pending writes of the same epoch of if the first write and the second write have the same epoch; and
update the first counter corresponding to a number of pending writes of an epoch of the first write and a second counter corresponding to a number of pending writes of an epoch of the second write if the first write and the second write do not have the same epoch.

6. A non-transitory computer-readable storage medium storing instructions thereon that, when executed, cause a processor to:
receive, by a fabric bridge, a first plurality of eviction requests from a first processor;
responsive to receiving each of the first eviction requests:
issue, by the fabric bridge, a first plurality of messages indicating that each of the first eviction requests were accepted by the fabric bridge; and
issue, by the fabric bridge, a first plurality of write requests to the fabric, wherein each of the first plurality of write requests correspond to each of the first plurality of eviction requests;

receive, by a fabric bridge, a second plurality of eviction requests from a second processor;
responsive to receiving each of the second eviction requests:
issue, by the fabric bridge, a second plurality of messages indicating that each of the second eviction requests were accepted by the fabric bridge; and
issue, by the fabric bridge, a second plurality of write requests to the fabric, wherein each of the second plurality of write requests correspond to each of the second plurality of eviction requests;

track the first plurality of write requests until each of the first write requests have persisted; and
track the second plurality of the second write requests until each of the second write requests have persisted
assign the first plurality of writes to a first epoch;
assign the second plurality of writes to a second epoch;
decrement a first counter associated with the first epoch responsive to receiving an acknowledgement via the fabric for one of the first plurality of writes; and
decrement a second counter associated with the second epoch responsive to receiving an acknowledgement via the fabric for one of the second plurality of writes.

7. The non-transitory computer-readable storage medium of claim 6 , storing instructions thereon that, when executed, cause the processor to:
transmit a first notification to the processor indicating the first plurality of write requests have persisted.

8. The non-transitory computer-readable storage medium of claim 7 , wherein the instructions that cause the processor to track the first plurality of writes comprise additional instructions that, when executed, cause the processor to receive a first request to read a status register, and
wherein the instructions that cause the processor to track the second plurality of writes comprise additional instructions that, when executed, cause the processor to receive a second request to read a status register.

9. The non-transitory computer-readable storage medium of claim 6 , comprising instructions that, when executed, cause the processor to:
receive, via the fabric, an acknowledgement for a persisted write request, the acknowledgement comprising an identifier;
determine an epoch of the persisted write request based on the identifier; and
determine whether one of the first pluralities of writes and the second pluralities of writes have persisted based on the determined epoch.

10. The non-transitory computer-readable storage medium of claim 6 , comprising instructions stored thereon that, when executed, cause the processor to:
determine whether the first pluralities of writes, and the second pluralities of writes have a same epoch; and
update a first counter indicating a number of pending writes of the same epoch of if the first plurality of writes and the second plurality of writes have the same epoch; and
update the first counter corresponding to a number of pending writes of an epoch of the first pluralities of writes and a second counter corresponding to a number of pending writes of an epoch of the second pluralities of writes if the first pluralities of writes and the second pluralities of writes do not have the same epoch.

11. A method, comprising:
receiving, by a fabric bridge, a first plurality of eviction requests from a first processor;
responsive to receiving each of the

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Sherlock Derek Alan
• Walker Shawn

Classifications

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F3/0685

  Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays · CPC title

• G06F3/0613 Primary

  in relation to throughput · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0658

  Controller construction arrangements · CPC title