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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-07-24 12:51:10 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-07-24 12:51:10 -0400 |
| commit | dc05973b288a5226bb7e56afd6c2fa07560a907c (patch) | |
| tree | 2e1eade8b6010ff4c844341fdeec9ee966d75ac7 /arch/arm64/mm/context.c | |
| parent | 297fae4d0bee5d683533f3324baf1b363e7b48bf (diff) | |
| parent | e7bdea7750eb2a64aea4a08fa5c0a31719c8155d (diff) | |
Merge commit 'e7bdea7750eb'
Needed in order to work on top of pNFS changes in Linus' upstream kernel.
Diffstat (limited to 'arch/arm64/mm/context.c')
| -rw-r--r-- | arch/arm64/mm/context.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index b7b397802088..efcf1f7ef1e4 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -179,7 +179,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) &asid_generation); flush_context(cpu); - /* We have at least 1 ASID per CPU, so this will always succeed */ + /* We have more ASIDs than CPUs, so this will always succeed */ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1); set_asid: @@ -227,8 +227,11 @@ switch_mm_fastpath: static int asids_init(void) { asid_bits = get_cpu_asid_bits(); - /* If we end up with more CPUs than ASIDs, expect things to crash */ - WARN_ON(NUM_USER_ASIDS < num_possible_cpus()); + /* + * Expect allocation after rollover to fail if we don't have at least + * one more ASID than CPUs. ASID #0 is reserved for init_mm. + */ + WARN_ON(NUM_USER_ASIDS - 1 <= num_possible_cpus()); atomic64_set(&asid_generation, ASID_FIRST_VERSION); asid_map = kzalloc(BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(*asid_map), GFP_KERNEL); |