Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-27 05:11:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

genirq/matrix: Handle CPU offlining proper

Browse Source 
At CPU hotunplug the corresponding per cpu matrix allocator is shut down and
the allocated interrupt bits are discarded under the assumption that all
allocated bits have been either migrated away or shut down through the
managed interrupts mechanism.

This is not true because interrupts which are not started up might have a
vector allocated on the outgoing CPU. When the interrupt is started up
later or completely shutdown and freed then the allocated vector is handed
back, triggering warnings or causing accounting issues which result in
suspend failures and other issues.

Change the CPU hotplug mechanism of the matrix allocator so that the
remaining allocations at unplug time are preserved and global accounting at
hotplug is correctly readjusted to take the dormant vectors into account.

Fixes: 2f75d9e1c9 ("genirq: Implement bitmap matrix allocator")
Reported-by: Yuriy Vostrikov <delamonpansie@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Yuriy Vostrikov <delamonpansie@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180222112316.849980972@linutronix.de
This commit is contained in:
Thomas Gleixner 2018-02-22 12:08:05 +01:00
parent 894266466a
commit 651ca2c004
1 changed files with 14 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
kernel/irq/matrix.c
View File

@ -16,6 +16,7 @@ struct cpumap {
unsigned int available;
unsigned int allocated;
unsigned int managed;
bool initialized;
bool online;
unsigned long alloc_map[IRQ_MATRIX_SIZE];
unsigned long managed_map[IRQ_MATRIX_SIZE];
@ -81,9 +82,11 @@ void irq_matrix_online(struct irq_matrix *m)
BUG_ON(cm->online);
bitmap_zero(cm->alloc_map, m->matrix_bits);
cm->available = m->alloc_size - (cm->managed + m->systembits_inalloc);
cm->allocated = 0;
if (!cm->initialized) {
cm->available = m->alloc_size;
cm->available -= cm->managed + m->systembits_inalloc;
cm->initialized = true;
}
m->global_available += cm->available;
cm->online = true;
m->online_maps++;
@ -370,15 +373,17 @@ void irq_matrix_free(struct irq_matrix *m, unsigned int cpu,
if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end))
return;
if (cm->online) {
clear_bit(bit, cm->alloc_map);
cm->allocated--;
if (cm->online)
m->total_allocated--;
if (!managed) {
cm->available++;
if (cm->online)
m->global_available++;
}
}
trace_irq_matrix_free(bit, cpu, m, cm);
}