International Business Machines Corporation

Gaurav Batra

Sreenivas Makineedi

Douglas J Griffith

Demetrice Browder

Mark D Rogers

Jacqueline Hegedus Wilson

Guha Prasad Venkataraman

Arnold Flores

Glen Edmond Chalemin

Charles A Kunzinger

Jaime A Jaloma

Anil Kumar Kaniveedu Damodaran

Amarendar N Sulu

Dave Kemper

Anil Kumar K Damodaran

During a memory reallocation process, it is determined that a set of memory pages being reallocated are each enabled for a Direct Memory Access (DMA) operation. Prior to writing initial data to the set of memory pages, a pre-access delay is performed concurrently for each memory page in the set of memory pages.

Minimizing delay while migrating direct memory access (DMA) mapped pages

A system and method tests computer software using tracking bits in branch instructions to track portions of the software that have been tested. The tracking bits are bits of a branch programming instruction and may be repurposed hint bits used in the prior art to control pre-fetch of instructions. A branch tracking unit sets bits in a branch instruction of an application or program being tested. The branch tracing unit sets a first bit if a branch is taken and sets a second tracking bit if the branch is not taken. The modified program instructions can be analyzed after running the test inputs to determine if any branches in the software have not been exercised by the test inputs.

Testing computer software using tracking bits

Sharing read-only data among virtual machines (VM) using an attached coherent accelerator processor interface (CAPI) enabled flash storage (CeFS) is provided. The method includes mapping a file, by a virtual machine monitor, from the CeFS into a range of common memory in the virtual machine monitor. The VM shares the mapped file with at least one other VM at a range of common memory in their address spaces. A redirect-on-write filesystem (RoWFS) is created on the VM and the at least one other VM, whereby the RoWFS includes a read-only copy and a private copy of a linear memory map of the mapped file. A data page is read using the copy of the linear memory map, and the data page is modified using the private copy of the linear memory map.

Sharing read-only data among virtual machines using coherent accelerator processor interface (CAPI) enabled flash

A method for setting a compression ratio for utilizing a compressed memory pool (which is backed by pinned memory) by a virtual memory manager (VMM). Compression of pages of corresponding segments can be tracked as part of a VMM paging algorithm that compresses pages to store in a compressed memory pool. A segment having pages with an average compression ratio below a threshold is identified. The identified segment pages are prevented from utilizing the compressed memory pool resulting in optimizing the use of the compressed memory pool.

Method to improve page out mechanism with compressed memory pools

A system and method for setting a compression ratio for utilizing a compressed memory pool (which is backed by pinned memory) by a virtual memory manager (VMM). Compression of pages of corresponding segments can be tracked as part of a VMM paging algorithm that compresses pages to store in a compressed memory pool. A segment having pages with an average compression ratio below a threshold is identified. The identified segment pages are prevented from utilizing the compressed memory pool resulting in optimizing the use of the compressed memory pool.

Apparatus, method and program product for relocating Bad Block Relocation Directory (BBRD) on a disk storage pre-allocate a number of areas for BBRD in different locations of the disk storage. The locations for the BBRD are calculated based upon the size of the disk and BBRD count. If the update of BBRD fails due to defective media at the location to be updated, that location is abandon and the next pre-allocated location is used. A copy of the BBRD is stored in RAM and maintained by the kernel. By so doing, when a bad block in the BBRD is detected the kernel causes the BBRD to be written in a good one of the locations reserved for BBRD. When the number of alternate BBRD locations used hits a pre-defined threshold, this indicates a situation where many sections of the disk are going bad and the disk needs replacement. If all BBRD locations are used, the disk is presumed bad and all future I/O activities to the disk is suspended. An administrator may be notified that the disk is going bad and needs to be replaced.

Relocating bad block relocation (BBR) directory upon encountering physical media defect on a disk

A data processing system, method, and product are disclosed for automatically configuring IP security tunnels. A security policy specification format is established that is capable of being utilized by any one of multiple different operating systems and any one of multiple different machine types. An IP security tunnel is automatically configured utilizing the security policy specification format.

Growing community of inventors

Cedar Park, TX, United States of America

Gaurav Batra