[PATCH] Proposal to remove workqueue usage from request_firmware_async()

From: Manuel Estrada Sainz
Date: Tue Oct 21 2003 - 08:26:49 EST


Michael Hunold also confirmed that it works for him, IMHO it should be
safe at least for the -mm tree.

The only difference with the previous patch is:

-daemonize("%s/%s", "firmware", fw_work->name);
+daemonize("firmware/%s", fw_work->name);

ChangeLog:

In it's current form request_firmware sleeps for too long on the system's
common workqueue, and using a private workqueue as previously proposed is not
optimal. This patch creates one kernel_thread for each
request_firmware_async() invocation which dies once the job is done.


firmware_class.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)


Index: drivers/base/firmware_class.c
===================================================================
--- linux-2.5/drivers/base/firmware_class.c (revision 14117)
+++ linux-2.5/drivers/base/firmware_class.c (working copy)
@@ -415,18 +415,22 @@
void (*cont)(const struct firmware *fw, void *context);
};

-static void
+static int
request_firmware_work_func(void *arg)
{
struct firmware_work *fw_work = arg;
const struct firmware *fw;
- if (!arg)
- return;
+ if (!arg) {
+ WARN_ON(1);
+ return 0;
+ }
+ daemonize("firmware/%s", fw_work->name);
request_firmware(&fw, fw_work->name, fw_work->device);
fw_work->cont(fw, fw_work->context);
release_firmware(fw);
module_put(fw_work->module);
kfree(fw_work);
+ return 0;
}

/**
@@ -451,6 +455,8 @@
{
struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
GFP_ATOMIC);
+ int ret;
+
if (!fw_work)
return -ENOMEM;
if (!try_module_get(module)) {
@@ -465,9 +471,14 @@
.context = context,
.cont = cont,
};
- INIT_WORK(&fw_work->work, request_firmware_work_func, fw_work);

- schedule_work(&fw_work->work);
+ ret = kernel_thread(request_firmware_work_func, fw_work,
+ CLONE_FS | CLONE_FILES);
+
+ if (ret < 0) {
+ fw_work->cont(NULL, fw_work->context);
+ return ret;
+ }
return 0;
}


--
--- Manuel Estrada Sainz <ranty@xxxxxxxxxx>
<ranty@xxxxxxxxxxx>
<ranty@xxxxxxxxxxxxxxxxxxxxx>
------------------------ <manuel.estrada@xxxxxxxxxxxxx> -------------------
Let us have the serenity to accept the things we cannot change, courage to
change the things we can, and wisdom to know the difference.
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