* [PATCH v4] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held
@ 2015-10-29 15:30 Saurabh Sengar
2015-11-06 21:51 ` Richard Weinberger
0 siblings, 1 reply; 2+ messages in thread
From: Saurabh Sengar @ 2015-10-29 15:30 UTC (permalink / raw)
To: jdike, richard, user-mode-linux-devel, user-mode-linux-user,
linux-kernel
Cc: Saurabh Sengar
since GFP_KERNEL with GFP_ATOMIC while spinlock is held,
as code while holding a spinlock should be atomic.
GFP_KERNEL may sleep and can cause deadlock,
where as GFP_ATOMIC may fail but certainly avoids deadlockdex f70dd54..d898f6c 100644
Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
---
v4: fixing comments from Joe and Richard
- removed variable gfp_mask in caller function
- changed its type from int to gfp_t in called function
arch/um/drivers/net_kern.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index f70dd54..9ef669d 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -388,7 +388,7 @@ static const struct net_device_ops uml_netdev_ops = {
static int driver_registered;
static void eth_configure(int n, void *init, char *mac,
- struct transport *transport)
+ struct transport *transport, gfp_t gfp_mask)
{
struct uml_net *device;
struct net_device *dev;
@@ -397,7 +397,7 @@ static void eth_configure(int n, void *init, char *mac,
size = transport->private_size + sizeof(struct uml_net_private);
- device = kzalloc(sizeof(*device), GFP_KERNEL);
+ device = kzalloc(sizeof(*device), gfp_mask);
if (device == NULL) {
printk(KERN_ERR "eth_configure failed to allocate struct "
"uml_net\n");
@@ -568,7 +568,7 @@ static LIST_HEAD(transports);
static LIST_HEAD(eth_cmd_line);
static int check_transport(struct transport *transport, char *eth, int n,
- void **init_out, char **mac_out)
+ void **init_out, char **mac_out, gfp_t gfp_mask)
{
int len;
@@ -582,7 +582,7 @@ static int check_transport(struct transport *transport, char *eth, int n,
else if (*eth != '\0')
return 0;
- *init_out = kmalloc(transport->setup_size, GFP_KERNEL);
+ *init_out = kmalloc(transport->setup_size, gfp_mask);
if (*init_out == NULL)
return 1;
@@ -609,11 +609,11 @@ void register_transport(struct transport *new)
list_for_each_safe(ele, next, ð_cmd_line) {
eth = list_entry(ele, struct eth_init, list);
match = check_transport(new, eth->init, eth->index, &init,
- &mac);
+ &mac, GFP_KERNEL);
if (!match)
continue;
else if (init != NULL) {
- eth_configure(eth->index, init, mac, new);
+ eth_configure(eth->index, init, mac, new, GFP_KERNEL);
kfree(init);
}
list_del(ð->list);
@@ -631,10 +631,11 @@ static int eth_setup_common(char *str, int index)
spin_lock(&transports_lock);
list_for_each(ele, &transports) {
transport = list_entry(ele, struct transport, list);
- if (!check_transport(transport, str, index, &init, &mac))
+ if (!check_transport(transport, str, index, &init,
+ &mac, GFP_ATOMIC))
continue;
if (init != NULL) {
- eth_configure(index, init, mac, transport);
+ eth_configure(index, init, mac, transport, GFP_ATOMIC);
kfree(init);
}
found = 1;
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v4] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held
2015-10-29 15:30 [PATCH v4] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held Saurabh Sengar
@ 2015-11-06 21:51 ` Richard Weinberger
0 siblings, 0 replies; 2+ messages in thread
From: Richard Weinberger @ 2015-11-06 21:51 UTC (permalink / raw)
To: Saurabh Sengar, jdike, user-mode-linux-devel,
user-mode-linux-user, linux-kernel
Am 29.10.2015 um 16:30 schrieb Saurabh Sengar:
> since GFP_KERNEL with GFP_ATOMIC while spinlock is held,
> as code while holding a spinlock should be atomic.
> GFP_KERNEL may sleep and can cause deadlock,
> where as GFP_ATOMIC may fail but certainly avoids deadlockdex f70dd54..d898f6c 100644
>
> Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Applied!
Thanks,
//richard
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-11-06 21:51 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-10-29 15:30 [PATCH v4] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held Saurabh Sengar
2015-11-06 21:51 ` Richard Weinberger
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).