diff options
| author | Jack Wang <jinpu.wang@ionos.com> | 2023-09-06 15:17:12 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-09-06 23:55:09 +0200 |
| commit | 3d7d72a34e05b23e21bafc8bfb861e73c86b31f3 (patch) | |
| tree | a17c8b3aa649bdc54dbbaa8b903fa89a49ad5ca6 | |
| parent | 659df86a7b2fe98feb5f4ec880e694caaebd27ae (diff) | |
x86/sgx: Break up long non-preemptible delays in sgx_vepc_release()
On large enclaves we hit the softlockup warning with following call trace:
xa_erase()
sgx_vepc_release()
__fput()
task_work_run()
do_exit()
The latency issue is similar to the one fixed in:
8795359e35bc ("x86/sgx: Silence softlockup detection when releasing large enclaves")
The test system has 64GB of enclave memory, and all is assigned to a single VM.
Release of 'vepc' takes a longer time and causes long latencies, which triggers
the softlockup warning.
Add cond_resched() to give other tasks a chance to run and reduce
latencies, which also avoids the softlockup detector.
[ mingo: Rewrote the changelog. ]
Fixes: 540745ddbc70 ("x86/sgx: Introduce virtual EPC for use by KVM guests")
Reported-by: Yu Zhang <yu.zhang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Yu Zhang <yu.zhang@ionos.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Haitao Huang <haitao.huang@linux.intel.com>
Cc: stable@vger.kernel.org
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/virt.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index c3e37eaec8ec..7aaa3652e31d 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -204,6 +204,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) continue; xa_erase(&vepc->page_array, index); + cond_resched(); } /* @@ -222,6 +223,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) list_add_tail(&epc_page->list, &secs_pages); xa_erase(&vepc->page_array, index); + cond_resched(); } /* @@ -243,6 +245,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file) if (sgx_vepc_free_page(epc_page)) list_add_tail(&epc_page->list, &secs_pages); + cond_resched(); } if (!list_empty(&secs_pages)) |