diff mbox

[v1,1/6] sparc64: reset mm cpumask after wrap

Message ID 1496244325-180257-2-git-send-email-pasha.tatashin@oracle.com
State Accepted
Delegated to: David Miller
Headers show

Commit Message

Pavel Tatashin May 31, 2017, 3:25 p.m. UTC 
After a wrap (getting a new context version) a process must get a new
context id, which means that we would need to flush the context id from
the TLB before running for the first time with this ID on every CPU. But,
we use mm_cpumask to determine if this process has been running on this CPU
before, and this mask is not reset after a wrap. So, there are two possible
fixes for this issue:

1. Clear mm cpumask whenever mm gets a new context id
2. Unconditionally flush context every time process is running on a CPU

This patch implements the first solution

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
---
 arch/sparc/mm/init_64.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
diff mbox

Patch

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 0cda653..e679b14 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -758,6 +758,8 @@  void get_new_mmu_context(struct mm_struct *mm)
 			goto out;
 		}
 	}
+	if (mm->context.sparc64_ctx_val)
+		cpumask_clear(mm_cpumask(mm));
 	mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63));
 	new_ctx |= (tlb_context_cache & CTX_VERSION_MASK);
 out: