(2013/04/11 22:00), Ric Mason wrote: > Hi Mitsuhiro, > On 04/11/2013 08:51 PM, Mitsuhiro Tanino wrote: >> (2013/04/11 12:53), Simon Jeons wrote: >>> One question against mce instead of the patchset. ;-) >>> >>> When check memory is bad? Before memory access? Is there a process scan it period? >> Hi Simon-san, >> >> Yes, there is a process to scan memory periodically. >> >> At Intel Nehalem-EX and CPUs after Nehalem-EX generation, MCA recovery >> is supported. MCA recovery provides error detection and isolation >> features to work together with OS. >> One of the MCA Recovery features is Memory Scrubbing. It periodically >> checks memory in the background of OS. > > Memory Scrubbing is a kernel thread? Where is the codes of memory scrubbing? Hi Ric, No. One of the MCA Recovery features is Memory Scrubbing. And Memory Scrubbing is a hardware feature of Intel CPU. OS has a hwpoison feature which is included at mm/memory-failure.c. A main function is memory_failure(). If Memory Scrubbing finds a memory error, MCA recovery notifies SRAO error into OS and OS handles the SRAO error using hwpoison function. >> If Memory Scrubbing find an uncorrectable error on a memory before >> OS accesses the memory bit, MCA recovery notifies SRAO error into OS > > It maybe can't find memory error timely since it is sleeping when memory error occur, can this case happened? Memory Scrubbing seems to be operated periodically but I don't have information about how oftern it is executed. Regards, Mitsuhiro Tanino -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>