公开(公告)号：US20190087333A1

公开(公告)日：2019-03-21

申请号：US16129451

申请日：2018-09-12

Applicant: QUALCOMM Incorporated

Inventor： Eric Francis Robinson ,  Thomas Philip Speier ,  Joseph Gerald McDonald ,  Garrett Michael Drapala ,  Kevin Neal Magill

IPC: G06F12/0815 ,  G06F13/40 ,  G06F13/16

Abstract: Converting a stale cache memory unique request to a read unique snoop response in a multiple (multi-) central processing unit (CPU) processor is disclosed. The multi-CPU processor includes a plurality of CPUs that each have access to either private or shared cache memories in a cache memory system. Multiple CPUs issuing unique requests to write data to a same coherence granule in a cache memory causes one unique request for a requested CPU to be serviced or “win” to allow that CPU to obtain the coherence granule in a unique state, while the other unsuccessful unique requests become stale. To avoid retried unique requests being reordered behind other pending, younger requests which would lead to lack of forward progress due to starvation or livelock, the snooped stale unique requests are converted to read unique snoop responses so that their request order can be maintained in the cache memory system.

公开(公告)号：US11226910B2

公开(公告)日：2022-01-18

申请号：US16808073

申请日：2020-03-03

Applicant: QUALCOMM Incorporated

Inventor： Joseph Gerald McDonald ,  Garrett Michael Drapala ,  Eric Francis Robinson ,  Thomas Philip Speier ,  Kevin Neal Magill ,  Richard Gerard Hofmann

IPC: G06F13/20 ,  G06F9/48

Abstract: Disclosed are ticketed flow control mechanisms in a processing system with one or more masters and one or more slaves. In an aspect, a targeted slave receives a request from a requesting master. If the targeted slave is unavailable to service the request, a ticket for the request is provided to the requesting master. As resources in the targeted slave become available, messages are broadcasted for the requesting master to update the ticket value. When the ticket value has been updated to a final value, the requesting master may re-transmit the request.