The patch titled
i386: in assign_irq_vector look at all vectors before giving up
has been added to the -mm tree. Its filename is
i386-in-assign_irq_vector-look-at-all-vectors-before-giving-up.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: i386: in assign_irq_vector look at all vectors before giving up
From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
When the world was a simple and static place setting up irqs was easy. It
sufficed to allocate a linux irq number and a find a free cpu vector we
could receive that linux irq on. In those days it was a safe assumption
that any allocated vector was actually in use so after one global pass
through all of the vectors we would have none left.
These days things are much more dynamic with interrupt controllers (in the
form of MSI or MSI-X) appearing on plug in cards and linux irqs appearing
and disappearing. As these irqs come and go vectors are allocated and
freed, invalidating the ancient assumption that all allocated vectors
stayed in use forever.
So this patch modifies the vector allocator to walk through every possible
vector before giving up, and to check to see if a vector is in use before
assigning it. With these changes we stop leaking freed vectors and it
becomes possible to allocate and free irq vectors all day long.
This changed was modeled after the vector allocator on x86_64 where this
limitation has already been removed. In essence we don't update the static
variables that hold the position of the last vector we allocated until have
successfully allocated another vector. This allows us to detect if we have
completed one complete scan through all of the possible vectors.
Acked-by: Auke Kok <auke-jan.h.kok@xxxxxxxxx>
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/i386/kernel/io_apic.c | 32 +++++++++++++++++++-------------
1 files changed, 19 insertions(+), 13 deletions(-)
diff -puN arch/i386/kernel/io_apic.c~i386-in-assign_irq_vector-look-at-all-vectors-before-giving-up arch/i386/kernel/io_apic.c
--- a/arch/i386/kernel/io_apic.c~i386-in-assign_irq_vector-look-at-all-vectors-before-giving-up
+++ a/arch/i386/kernel/io_apic.c
@@ -1227,26 +1227,32 @@ static u8 irq_vector[NR_IRQ_VECTORS] __r
static int __assign_irq_vector(int irq)
{
- static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
- int vector;
+ static int current_vector = FIRST_DEVICE_VECTOR, current_offset = 0;
+ int vector, offset, i;
BUG_ON((unsigned)irq >= NR_IRQ_VECTORS);
if (irq_vector[irq] > 0)
return irq_vector[irq];
- current_vector += 8;
- if (current_vector == SYSCALL_VECTOR)
- current_vector += 8;
-
- if (current_vector >= FIRST_SYSTEM_VECTOR) {
- offset++;
- if (!(offset % 8))
- return -ENOSPC;
- current_vector = FIRST_DEVICE_VECTOR + offset;
- }
-
vector = current_vector;
+ offset = current_offset;
+next:
+ vector += 8;
+ if (vector >= FIRST_SYSTEM_VECTOR) {
+ offset = (offset + 1) % 8;
+ vector = FIRST_DEVICE_VECTOR + offset;
+ }
+ if (vector == current_vector)
+ return -ENOSPC;
+ if (vector == SYSCALL_VECTOR)
+ goto next;
+ for (i = 0; i < NR_IRQ_VECTORS; i++)
+ if (irq_vector[i] == vector)
+ goto next;
+
+ current_vector = vector;
+ current_offset = offset;
irq_vector[irq] = vector;
return vector;
_
Patches currently in -mm which might be from ebiederm@xxxxxxxxxxxx are
origin.patch
namespaces-fix-exit-race-by-splitting-exit.patch
i386-in-assign_irq_vector-look-at-all-vectors-before-giving-up.patch
powerpc-rtas-msi-support.patch
kthread-api-conversion-for-dvb_frontend-and-av7110.patch
bugfixes-pci-devices-get-assigned-redundant-irqs.patch
kexec-update-io-apic-dest-field-to-8-bit-for.patch
vt-refactor-console-sak-processing.patch
sysctl_ms_jiffies-fix-oldlen-semantics.patch
9p-use-kthread_stop-instead-of-sending-a-sigkill.patch
procfs-fix-race-between-proc_readdir-and-remove_proc_entry.patch
procfs-fix-race-between-proc_readdir-and-remove_proc_entry-fix.patch
kill_pid_info-kill-acquired_tasklist_lock.patch
clone-flag-clone_parent_tidptr-leaves-invalid-results-in-memory.patch
fix-rmmod-read-write-races-in-proc-entries.patch
tty-make-__proc_set_tty-static.patch
tty-clarify-disassociate_ctty.patch
tty-fix-the-locking-for-signal-session-in-disassociate_ctty.patch
signal-use-kill_pgrp-not-kill_pg-in-the-sunos-compatibility-code.patch
signal-rewrite-kill_something_info-so-it-uses-newer-helpers.patch
pid-make-session_of_pgrp-use-struct-pid-instead-of-pid_t.patch
pid-use-struct-pid-for-talking-about-process-groups-in-exitc.patch
pid-replace-is_orphaned_pgrp-with-is_current_pgrp_orphaned.patch
tty-update-the-tty-layer-to-work-with-struct-pid.patch
pid-replace-do-while_each_task_pid-with-do-while_each_pid_task.patch
pid-remove-now-unused-do_each_task_pid-and-while_each_task_pid.patch
pid-remove-the-now-unused-kill_pg-kill_pg_info-and-__kill_pg_info.patch
i386-apic-clean-up-the-apic-code.patch
i386-rework-local-apic-timer-calibration.patch
i386-prepare-nmi-watchdog-for-dynticks.patch
edac-e752x-bit-mask-fix.patch
edac-e752x-byte-access-fix.patch
edac-k8-driver-coding-tidy.patch
sched2-sched-domain-sysctl-use-ctl_unnumbered.patch
mm-implement-swap-prefetching-use-ctl_unnumbered.patch
introduce-and-use-get_task_mnt_ns.patch
introduce-and-use-get_task_mnt_ns-tweaks.patch
nsproxy-externalizes-exit_task_namespaces.patch
user-namespace-add-the-framework.patch
user-namespace-add-the-framework-fix.patch
user-ns-add-user_namespace-ptr-to-vfsmount.patch
user-ns-hook-permission.patch
user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs.patch
user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs-fix.patch
user-ns-implement-shared-mounts.patch
user_ns-handle-file-sigio.patch
user_ns-handle-file-sigio-fix.patch
user_ns-handle-file-sigio-fix-2.patch
user-ns-implement-user-ns-unshare.patch
user-ns-implement-user-ns-unshare-tidy.patch
remove-find_attach_pid.patch
statically-initialize-struct-pid-for-swapper.patch
explicitly-set-pgid-sid-of-init.patch
uts-namespace-remove-config_uts_ns.patch
ipc-namespace-remove-config_ipc_ns.patch
ipc-namespace-remove-config_ipc_ns-linkage-fix.patch
ipc-namespace-remove-config_ipc_ns-linkage-fix-fix.patch
readahead-sysctl-parameters-use-ctl_unnumbered.patch
sysctl-x25-remove-unnecessary-insert_at_head-from-register_sysctl_table.patch
sysctl-move-ctl_sunrpc-to-sysctlh-where-it-belongs.patch
sysctl-sunrpc-remove-unnecessary-insert_at_head-flag.patch
sysctl-sunrpc-dont-unnecessarily-set-ctl_table-de.patch
sysctl-rose-remove-unnecessary-insert_at_head-flag.patch
sysctl-netrom-remove-unnecessary-insert_at_head-flag.patch
sysctl-llc-remove-unnecessary-insert_at_head-flag.patch
sysctl-ipx-remove-unnecessary-insert_at_head-flag.patch
sysctl-decnet-remove-unnecessary-insert_at_head-flag.patch
sysctl-dccp-remove-unnecessary-insert_at_head-flag.patch
sysctl-ax25-remove-unnecessary-insert_at_head-flag.patch
sysctl-atalk-remove-unnecessary-insert_at_head-flag.patch
sysctl-xfs-remove-unnecessary-insert_at_head-flag.patch
sysctl-c99-convert-xfs-ctl_tables.patch
sysctl-c99-convert-xfs-ctl_tables-fixes.patch
sysctl-scsi-remove-unnecessary-insert_at_head-flag.patch
sysctl-md-remove-unnecessary-insert_at_head-flag.patch
sysctl-mac_hid-remove-unnecessary-insert_at_head-flag.patch
sysctl-ipmi-remove-unnecessary-insert_at_head-flag.patch
sysctl-cdrom-remove-unnecessary-insert_at_head-flag.patch
sysctl-cdrom-dont-set-de-owner.patch
sysctl-move-ctl_pm-into-sysctlh-where-it-belongs.patch
sysctl-frv-pm-remove-unnecessary-insert_at_head-flag.patch
sysctl-move-ctl_frv-into-sysctlh-where-it-belongs.patch
sysctl-frv-remove-unnecessary-insert_at_head-flag.patch
sysctl-c99-convert-arch-frv-kernel-pmc.patch
sysctl-c99-convert-arch-frv-kernel-sysctlc.patch
sysctl-sn-remove-sysctl-abi-breakage.patch
sysctl-c99-convert-arch-ia64-sn-kernel-xpc_mainc.patch
sysctl-c99-convert-arch-ia64-kernel-perfmon-and-remove-abi-breakage.patch
sysctl-mips-au1000-remove-sys_sysctl-support.patch
sysctl-c99-convert-the-ctl_tables-in-arch-mips-au1000-common-powerc.patch
sysctl-c99-convert-arch-mips-lasat-sysctlc-and-remove-abi-breakage.patch
sysctl-s390-move-sysctl-definitions-to-sysctlh.patch
sysctl-s390-remove-unnecessary-use-of-insert_at_head.patch
sysctl-c99-convert-ctl_tables-in-arch-powerpc-kernel-idlec.patch
sysctl-c99-convert-ctl_tables-entries-in-arch-ppc-kernel-ppc_htabc.patch
sysctl-c99-convert-arch-sh64-kernel-trapsc-and-remove-abi-breakage.patch
sysctl-x86_64-remove-unnecessary-use-of-insert_at_head.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-ia32-ia32_binfmtc.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-kernel-vsyscallc.patch
sysctl-c99-convert-ctl_tables-in-arch-x86_64-mm-initc.patch
sysctl-remove-sys_sysctl-support-from-the-hpet-timer-driver.patch
sysctl-remove-sys_sysctl-support-from-drivers-char-rtcc.patch
sysctl-register-the-sysctl-number-used-by-the-arlan-driver.patch
sysctl-c99-convert-ctl_tables-in-drivers-parport-procfsc.patch
sysctl-c99-convert-ctl_tables-in-drivers-parport-procfsc-fix.patch
sysctl-c99-convert-coda-ctl_tables-and-remove-binary-sysctls.patch
sysctl-c99-convert-ctl_tables-in-ntfs-and-remove-sys_sysctl-support.patch
sysctl-c99-convert-ctl_tables-in-ntfs-and-remove-sys_sysctl-support-fix.patch
sysctl-register-the-ocfs2-sysctl-numbers.patch
sysctl-move-init_irq_proc-into-init-main-where-it-belongs.patch
sysctl-move-utsname-sysctls-to-their-own-file.patch
sysctl-move-utsname-sysctls-to-their-own-file-fix.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file-fix.patch
sysctl-create-sys-fs-binfmt_misc-as-an-ordinary-sysctl-entry.patch
sysctl-create-sys-fs-binfmt_misc-as-an-ordinary-sysctl-entry-warning-fix.patch
sysctl-remove-support-for-ctl_any.patch
sysctl-remove-support-for-directory-strategy-routines.patch
sysctl-remove-insert_at_head-from-register_sysctl.patch
sysctl-remove-insert_at_head-from-register_sysctl-fix.patch
sysctl-factor-out-sysctl_head_next-from-do_sysctl.patch
sysctl-factor-out-sysctl_head_next-from-do_sysctl-warning-fix.patch
sysctl-allow-sysctl_perm-to-be-called-from-outside-of-sysctlc.patch
sysctl-reimplement-the-sysctl-proc-support.patch
sysctl-reimplement-the-sysctl-proc-support-fix.patch
sysctl-reimplement-the-sysctl-proc-support-warning-fix.patch
sysctl-reimplement-the-sysctl-proc-support-fix-2.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables-fix.patch
sysctl-remove-the-proc_dir_entry-member-for-the-sysctl-tables-ntfs-fix.patch
vdso-print-fatal-signals-use-ctl_unnumbered.patch
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