Nathan Lynch 9d6792ffe1 powerpc/pseries: explicitly reschedule during drmem_lmb list traversal ... The drmem lmb list can have hundreds of thousands of entries, and unfortunately lookups take the form of linear searches. As long as this is the case, traversals have the potential to monopolize the CPU and provoke lockup reports, workqueue stalls, and the like unless they explicitly yield. Rather than placing cond_resched() calls within various for_each_drmem_lmb() loop blocks in the code, put it in the iteration expression of the loop macro itself so users can't omit it. Introduce a drmem_lmb_next() iteration helper function which calls cond_resched() at a regular interval during array traversal. Each iteration of the loop in DLPAR code paths can involve around ten RTAS calls which can each take up to 250us, so this ensures the check is performed at worst every few milliseconds. Fixes: 6c6ea53725 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200813151131.2070161-1-nathanl@linux.ibm.com		2020-09-02 11:00:20 +10:00
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asm	powerpc/pseries: explicitly reschedule during drmem_lmb list traversal	2020-09-02 11:00:20 +10:00
uapi/asm	powerpc/perf: Add extended regs support for power10 platform	2020-08-17 13:11:22 +10:00