On 9/2/2024 9:37 AM, Huang, Ying wrote:
Yanfei Xu <yanfei.xu@xxxxxxxxx> writes:
[Snip]
On 8/30/2024 3:11 PM, Huang, Ying wrote:
Fixes: 823430c8e9d9 ("memory tier: consolidate the initialization of memory tiers")
Signed-off-by: Yanfei Xu<yanfei.xu@xxxxxxxxx>
---
mm/memory-tiers.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 4775b3a3dabe..dddcd6b38e28 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -895,7 +895,6 @@ static int __init memory_tier_init(void)
WARN_ON(!node_demotion);
#endif
- guard(mutex)(&memory_tier_lock);
/*
* For now we can have 4 faster memory tiers with smaller adistance
* than default DRAM tier.
Although it's not absolutely necessary, I still think that it's better
to just revert the locking change of memory_tier_init() in commit
823430c8e9d9 ("memory tier: consolidate the initialization of memory
tiers"). That is, to use mutex_lock/unlock() and exclude
hotplug_memory_notifier() from the locked region. Because we will
always hold memory_tier_lock when working on memory tier related data
structures in this way.
Thanks for pointing out it. Will do it as below in v2.
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 4775b3a3dabe..ba3738b29cc5 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -895,13 +895,14 @@ static int __init memory_tier_init(void)
WARN_ON(!node_demotion);
#endif
- guard(mutex)(&memory_tier_lock);
+ mutex_lock(&memory_tier_lock);
/*
* For now we can have 4 faster memory tiers with smaller adistance
* than default DRAM tier.
*/
default_dram_type =
mt_find_alloc_memory_type(MEMTIER_ADISTANCE_DRAM,
&default_memory_types);
+ mutex_unlock(&memory_tier_lock);
if (IS_ERR(default_dram_type))
panic("%s() failed to allocate default DRAM tier\n",
__func__);
LGTM, feel free to add in the future version.
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Hi Ying,
Thanks for your "Reviewed-by"! I sent the v2 last Friday evening. Could
you please reply to that thread with the "Reviewed-by"? If not, I can
send v3 and include your tag.
Thread name:
8/30/2024, 6:24 PM [PATCH v2] memory tier: fix deadlock warning while
onlining pages
Best Regards,
Yanfei
