Re: [PATCH] iwlwifi: pcie: make array prop static, shrinks object size
From: Joe Perches <joe@perches.com>
Date: 2018-06-11 19:41:05
Also in:
kernel-janitors, linux-wireless, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, intel wireless wifi link (iwlwifi), library code, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Miri Korenblit, Andrew Morton, Linus Torvalds
(adding Greg KH) On Mon, 2018-06-11 at 18:15 +0100, Colin King wrote:
quoted hunk ↗ jump to hunk
From: Colin Ian King <redacted> Don't populate the read-only array 'prop' on the stack but instead make it static. Makes the object code smaller by 20 bytes: Before: text data bss dec hex filename 71659 14614 576 86849 15341 trans.o After: text data bss dec hex filename 71479 14774 576 86829 1532d trans.o (gcc version 7.3.0 x86_64) Signed-off-by: Colin Ian King <redacted> --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index 7229991ae70d..c4626ebe5da1 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c@@ -1946,7 +1946,7 @@ static void iwl_trans_pcie_removal_wk(struct work_struct *wk) struct iwl_trans_pcie_removal *removal = container_of(wk, struct iwl_trans_pcie_removal, work); struct pci_dev *pdev = removal->pdev; - char *prop[] = {"EVENT=INACCESSIBLE", NULL}; + static char *prop[] = {"EVENT=INACCESSIBLE", NULL}; dev_err(&pdev->dev, "Device gone - attempting removal\n"); kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, prop);
Now what is happening is that prop is being reloaded each invocation with the constant addresses of the strings. It seems the prototype and function for kobject_uevent_env should change as well to avoid this. Perhaps this should become: --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 2 +- include/linux/kobject.h | 2 +- lib/kobject_uevent.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 7229991ae70d..6668a8aad22e 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c@@ -1946,7 +1946,7 @@ static void iwl_trans_pcie_removal_wk(struct work_struct *wk) struct iwl_trans_pcie_removal *removal = container_of(wk, struct iwl_trans_pcie_removal, work); struct pci_dev *pdev = removal->pdev; - char *prop[] = {"EVENT=INACCESSIBLE", NULL}; + static const char * const prop[] = {"EVENT=INACCESSIBLE", NULL}; dev_err(&pdev->dev, "Device gone - attempting removal\n"); kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, prop);
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 7f6f93c3df9c..9f5cf553dd1e 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h@@ -217,7 +217,7 @@ extern struct kobject *firmware_kobj; int kobject_uevent(struct kobject *kobj, enum kobject_action action); int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, - char *envp[]); + const char * const envp[]); int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); __printf(2, 3)
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 63d0816ab23b..9107989a0cc8 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c@@ -452,7 +452,7 @@ static void zap_modalias_env(struct kobj_uevent_env *env) * corresponding error when it fails. */ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, - char *envp_ext[]) + const char * const envp_ext[]) { struct kobj_uevent_env *env; const char *action_string = kobject_actions[action];