Hi Stewards: Since this is a bug fix, and the risk for this release is small. I plan to push this serial changes before edk2-stable201811 tag.
If you have any concern, please raise here. Thanks, Eric > -----Original Message----- > From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Eric > Dong > Sent: Thursday, November 8, 2018 10:58 AM > To: edk2-devel@lists.01.org > Cc: Ni, Ruiyu <ruiyu...@intel.com>; Laszlo Ersek <ler...@redhat.com> > Subject: [edk2] [Patch 0/2] Separate semaphore container. > > In current implementation, core level semaphore use same container with > package level semaphore. This design will let the core level semaphore not > works as expected in below case: > 1. Feature A has CPU_FEATURE_CORE_BEFORE dependence with Feature B. > 2. Feature C has CPU_FEATURE_PACKAGE_AFTER dependence with Feature B. > in this case an core level semaphore will be add between A and B, and an > package level semaphore will be add between B and C. > > For a CPU has one package, two cores and 4 threads. Execute like below: > > Thread 1 Thread 2 ..... Thread 4 > ReleaseSemaph(1,2) -| > WaitForSemaph(1(2)) -|<-----------------------These two are Core Semaph > ReleaseSemaph(1,2) -| > WaitForSemaph(2) -| <--- Core Semaph > > ReleaseSemaph (1,2,3,4) -| > WaitForSemaph (1(4)) -| <---------------- Package Semaph > > ReleaseSemaph(3,4) > WaitForSemaph(4(2)) <- Core Semaph > > In above case, for thread 4, when it executes a core semaphore, i will found > WaitForSemaph(4(2)) is met because Thread 1 has execute a package > semaphore and ReleaseSemaph(4) for it before. This is not an expect behavior. > Thread 4 should wait for thread 3 to do this. > > Fix this issue by separate the semaphore container for core level and package > level. > > Cc: Laszlo Ersek <ler...@redhat.com> > Cc: Ruiyu Ni <ruiyu...@intel.com> > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Eric Dong <eric.d...@intel.com> > > Eric Dong (2): > UefiCpuPkg/RegisterCpuFeaturesLib: Separate semaphore container. > UefiCpuPkg/PiSmmCpuDxeSmm: Separate semaphore container. > > .../RegisterCpuFeaturesLib/CpuFeaturesInitialize.c | 9 ++++++--- > .../RegisterCpuFeaturesLib/RegisterCpuFeatures.h | 7 ++++--- > UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 21 > ++++++++++++++------- > 3 files changed, 24 insertions(+), 13 deletions(-) > > -- > 2.15.0.windows.1 > > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.01.org > https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
