GHES: Seriously speedup and cleanup NMI handler (Jiri Kosina and Borislav Petkov)
This is the result of us seeing this during boot [ 24.332560] INFO: NMI handler (ghes_notify_nmi) took too long to run: 3.265 msecs [ 24.332567] INFO: NMI handler (ghes_notify_nmi) took too long to run: 5.946 msecs [ 24.332568] INFO: NMI handler (ghes_notify_nmi) took too long to run: 5.948 msecs and a report of people running perf stat and the machine softlocking. "hest_disable" was helping in this case, which made us look at that particular NMI handler. It was grabbing a lock each time it is run and on each CPU. But this is not needed as the GHES sources are global and they need only a single reader. This patchset does that and cleans up the handler in the process. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJVRzqjAAoJEBLB8Bhh3lVKFQUQAKmPPaWp2qPUkRHtrdFfae0n Um9PSAHlvO8oHPrr+5j+CEVX1gQ1qUFMuxSVuBYYhmMZnsAVCwKX8gOi3slZmElo L0MoqxygP2v3Rc79Jk8KEkov+80zzp46VoB5Yh0mTfzSejeS+c1owwS0RzVIpda3 Zp1cAThTVsCdDmmWGhnWfc8T/wniPc2zbbVhtjivO/wwSu7ArWUR5/03pbxzex8M 3xnJY29USB62xO5OJf0mxAIhTqv4a7NSQ6NziBrI2Mt4inHj0oSR7KLVFpeSx4mX LLo8dWfDpMIbwd2sZYg5fG6Kz2i3Cc5I252V4j7MI+srvvZzZPBr1aB8qNyQVGPF grrQKQuD2Az0WZRo2gK2LvxvlHfmJyOJMaFPW+RMnARbtKMmmAIwaN4+zmPGHoH8 aQK7cKUyb1JxICpy9iAZjXMvqxc5zbhYra0G+zuLKruhEvmLrwibphjI82BNdaBZ rhkK+cw47lPgwKVNRWKjpNGGziwqU2cBlmc50k9OyQhhv5HF2TeYyBRryykOVmLV DpsUxO4rCj0YEioyoJEruBO1Ks167HGrg5sbSemO/YeM7wLgr7hMfVNlGM4DI68X b3Ie81/7qD8d3nQZ/gkk8ex1D0QhS0FWZthbNKpvkX+Zc/ELbGhfgHxX55HmfGuD DUmvP2oXlALAIPiJAYVP =Qj+0 -----END PGP SIGNATURE----- Merge tag 'ras_for_4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into acpi-apei Pull GHES changes for 4.2 from Borislav Petkov: "GHES: Seriously speedup and cleanup NMI handler (Jiri Kosina and Borislav Petkov) This is the result of us seeing this during boot [ 24.332560] INFO: NMI handler (ghes_notify_nmi) took too long to run: 3.265 msecs [ 24.332567] INFO: NMI handler (ghes_notify_nmi) took too long to run: 5.946 msecs [ 24.332568] INFO: NMI handler (ghes_notify_nmi) took too long to run: 5.948 msecs and a report of people running perf stat and the machine softlocking. "hest_disable" was helping in this case, which made us look at that particular NMI handler. It was grabbing a lock each time it is run and on each CPU. But this is not needed as the GHES sources are global and they need only a single reader. This patchset does that and cleans up the handler in the process." * tag 'ras_for_4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: GHES: Make NMI handler have a single reader GHES: Elliminate double-loop in the NMI handler GHES: Panic right after detection GHES: Carve out the panic functionality GHES: Carve out error queueing in a separate function
This commit is contained in:
Rafael J. Wysocki
Коммит
20f34165a9
|
|
@ -729,10 +729,10 @@ static struct llist_head ghes_estatus_llist;
|
|||
static struct irq_work ghes_proc_irq_work;
|
||||
|
||||
/*
|
||||
* NMI may be triggered on any CPU, so ghes_nmi_lock is used for
|
||||
* mutual exclusion.
|
||||
* NMI may be triggered on any CPU, so ghes_in_nmi is used for
|
||||
* having only one concurrent reader.
|
||||
*/
|
||||
static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
|
||||
static atomic_t ghes_in_nmi = ATOMIC_INIT(0);
|
||||
|
||||
static LIST_HEAD(ghes_nmi);
|
||||
|
||||
|
|
@ -797,73 +797,75 @@ static void ghes_print_queued_estatus(void)
|
|||
}
|
||||
}
|
||||
|
||||
/* Save estatus for further processing in IRQ context */
|
||||
static void __process_error(struct ghes *ghes)
|
||||
{
|
||||
#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
|
||||
u32 len, node_len;
|
||||
struct ghes_estatus_node *estatus_node;
|
||||
struct acpi_hest_generic_status *estatus;
|
||||
|
||||
if (ghes_estatus_cached(ghes->estatus))
|
||||
return;
|
||||
|
||||
len = cper_estatus_len(ghes->estatus);
|
||||
node_len = GHES_ESTATUS_NODE_LEN(len);
|
||||
|
||||
estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, node_len);
|
||||
if (!estatus_node)
|
||||
return;
|
||||
|
||||
estatus_node->ghes = ghes;
|
||||
estatus_node->generic = ghes->generic;
|
||||
estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
|
||||
memcpy(estatus, ghes->estatus, len);
|
||||
llist_add(&estatus_node->llnode, &ghes_estatus_llist);
|
||||
#endif
|
||||
}
|
||||
|
||||
static void __ghes_panic(struct ghes *ghes)
|
||||
{
|
||||
oops_begin();
|
||||
ghes_print_queued_estatus();
|
||||
__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);
|
||||
|
||||
/* reboot to log the error! */
|
||||
if (panic_timeout == 0)
|
||||
panic_timeout = ghes_panic_timeout;
|
||||
panic("Fatal hardware error!");
|
||||
}
|
||||
|
||||
static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
|
||||
{
|
||||
struct ghes *ghes, *ghes_global = NULL;
|
||||
int sev, sev_global = -1;
|
||||
int ret = NMI_DONE;
|
||||
struct ghes *ghes;
|
||||
int sev, ret = NMI_DONE;
|
||||
|
||||
if (!atomic_add_unless(&ghes_in_nmi, 1, 1))
|
||||
return ret;
|
||||
|
||||
raw_spin_lock(&ghes_nmi_lock);
|
||||
list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
|
||||
if (ghes_read_estatus(ghes, 1)) {
|
||||
ghes_clear_estatus(ghes);
|
||||
continue;
|
||||
}
|
||||
|
||||
sev = ghes_severity(ghes->estatus->error_severity);
|
||||
if (sev > sev_global) {
|
||||
sev_global = sev;
|
||||
ghes_global = ghes;
|
||||
}
|
||||
if (sev >= GHES_SEV_PANIC)
|
||||
__ghes_panic(ghes);
|
||||
|
||||
if (!(ghes->flags & GHES_TO_CLEAR))
|
||||
continue;
|
||||
|
||||
__process_error(ghes);
|
||||
ghes_clear_estatus(ghes);
|
||||
|
||||
ret = NMI_HANDLED;
|
||||
}
|
||||
|
||||
if (ret == NMI_DONE)
|
||||
goto out;
|
||||
|
||||
if (sev_global >= GHES_SEV_PANIC) {
|
||||
oops_begin();
|
||||
ghes_print_queued_estatus();
|
||||
__ghes_print_estatus(KERN_EMERG, ghes_global->generic,
|
||||
ghes_global->estatus);
|
||||
/* reboot to log the error! */
|
||||
if (panic_timeout == 0)
|
||||
panic_timeout = ghes_panic_timeout;
|
||||
panic("Fatal hardware error!");
|
||||
}
|
||||
|
||||
list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
|
||||
#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
|
||||
u32 len, node_len;
|
||||
struct ghes_estatus_node *estatus_node;
|
||||
struct acpi_hest_generic_status *estatus;
|
||||
#endif
|
||||
if (!(ghes->flags & GHES_TO_CLEAR))
|
||||
continue;
|
||||
#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
|
||||
if (ghes_estatus_cached(ghes->estatus))
|
||||
goto next;
|
||||
/* Save estatus for further processing in IRQ context */
|
||||
len = cper_estatus_len(ghes->estatus);
|
||||
node_len = GHES_ESTATUS_NODE_LEN(len);
|
||||
estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
|
||||
node_len);
|
||||
if (estatus_node) {
|
||||
estatus_node->ghes = ghes;
|
||||
estatus_node->generic = ghes->generic;
|
||||
estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
|
||||
memcpy(estatus, ghes->estatus, len);
|
||||
llist_add(&estatus_node->llnode, &ghes_estatus_llist);
|
||||
}
|
||||
next:
|
||||
#endif
|
||||
ghes_clear_estatus(ghes);
|
||||
}
|
||||
#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
|
||||
irq_work_queue(&ghes_proc_irq_work);
|
||||
#endif
|
||||
|
||||
out:
|
||||
raw_spin_unlock(&ghes_nmi_lock);
|
||||
atomic_dec(&ghes_in_nmi);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче