From: Martin Belanger <martin.belanger@dell.com>
Date: Fri, 4 Nov 2022 18:53:44 +0000 (-0400)
Subject: python: Release GIL on blocking calls
X-Git-Tag: v1.3~40^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7d14a39b7d4af0a49cb76cf45467d353b14aaa28;p=users%2Fsagi%2Flibnvme.git

python: Release GIL on blocking calls

Release Python's GIL (global interpreter lock) when invoking blocking
functions from multithreaded Python applications. This is to prevent
long running threads to block all other threads.

Signed-off-by: Martin Belanger <martin.belanger@dell.com>
---

diff --git a/libnvme/nvme.i b/libnvme/nvme.i
index 6f20e2cc..0c6b73ca 100644
--- a/libnvme/nvme.i
+++ b/libnvme/nvme.i
@@ -585,7 +585,11 @@ struct nvme_ns {
       connect_err = 1;
       return;
     }
+
+    Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
     ret = nvmf_add_ctrl(h, $self, cfg);
+    Py_END_ALLOW_THREADS    /* Reacquire Python GIL */
+
     if (ret < 0) {
       connect_err = 2;
       return;
@@ -601,7 +605,9 @@ struct nvme_ns {
     nvme_rescan_ctrl($self);
   }
   void disconnect() {
+    Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
     nvme_disconnect_ctrl($self);
+    Py_END_ALLOW_THREADS    /* Reacquire Python GIL */
   }
 
   %feature("autodoc", "@return: True if controller supports explicit registration. False otherwise.") is_registration_supported;
@@ -614,7 +620,10 @@ struct nvme_ns {
     __u32 result;
     int   status;
 
+    Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
     status = nvmf_register_ctrl($self, NVMF_DIM_TAS_REGISTER, &result);
+    Py_END_ALLOW_THREADS    /* Reacquire Python GIL */
+
     if (status != NVME_SC_SUCCESS) {
       /* On error, return an error message */
       if (status < 0)
@@ -629,6 +638,7 @@ struct nvme_ns {
 
   %newobject discover;
   struct nvmf_discovery_log *discover(int lsp = 0, int max_retries = 6) {
+    struct nvmf_discovery_log *logp;
     struct nvme_get_discovery_args args = {
       .c = $self,
       .args_size = sizeof(args),
@@ -637,7 +647,11 @@ struct nvme_ns {
       .timeout = NVME_DEFAULT_IOCTL_TIMEOUT,
       .lsp = lsp,
     };
-    struct nvmf_discovery_log *logp = nvmf_get_discovery_wargs(&args);
+
+    Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
+    logp = nvmf_get_discovery_wargs(&args);
+    Py_END_ALLOW_THREADS    /* Reacquire Python GIL */
+
     if (logp == NULL)
       discover_err = 1;
     return logp;
@@ -649,7 +663,10 @@ struct nvme_ns {
     PyObject *obj = NULL;
     int ret = 0;
 
+    Py_BEGIN_ALLOW_THREADS  /* Release Python GIL */
     ret = nvme_get_log_supported_log_pages(nvme_ctrl_get_fd($self), rae, &log);
+    Py_END_ALLOW_THREADS    /* Reacquire Python GIL */
+
     if (ret < 0) {
       Py_RETURN_NONE;
     }