On 08/31/2015 10:48 PM, James Smart wrote:
>
> Note: original patch modified by me to resolve unused variable warning
>
> From: ian mitchell <imitchell@xxxxxxx>
>
> This patch allows the LPFC to start up without a fatal kernel bug based
> on an exceeded KMALLOC_MAX_SIZE and a too large NR_CPU-based maskbits
> field. The bug was based on the number of CPU cores in a system.
> Using the get_cpu_mask() function declared in kernel/cpu.c allows the
> driver to load on the community kernel 4.2 RC1.
>
> Below is the kernel bug reproduced:
>
> 8<--------------------------------------------------------------------
> 2199382.828437 ( 0.005216)| lpfc 0003:02:00.0: enabling device (0140 -> 0142)
> 2199382.999272 ( 0.170835)| ------------[ cut here ]------------
> 2199382.999337 ( 0.000065)| WARNING: CPU: 84 PID: 404 at mm/slab_common.c:653 kmalloc_slab+0x2f/0x89()
> 2199383.004534 ( 0.005197)| Modules linked in: lpfc(+) usbcore(+) mptctl scsi_transport_fc sg lpc_ich i2c_i801 usb_common tpm_tis mfd_core tpm acpi_cpufreq button scsi_dh_alua scsi_dh_rdacusbcore: registered new device driver usb
> 2199383.020568 ( 0.016034)|
> 2199383.020581 ( 0.000013)| scsi_dh_hp_sw scsi_dh_emc scsi_dh gru thermal sata_nv processor piix fan thermal_sysehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
> 2199383.035288 ( 0.014707)|
> 2199383.035306 ( 0.000018)| hwmon ata_piix
> 2199383.035336 ( 0.000030)| CPU: 84 PID: 404 Comm: kworker/84:0 Not tainted 3.18.0-rc2-gat-00106-ga7ca10f-dirty #178
> 2199383.047077 ( 0.011741)| ehci-pci: EHCI PCI platform driver
> 2199383.047134 ( 0.000057)| Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
> 2199383.056245 ( 0.009111)| Workqueue: events work_for_cpu_fn
> 2199383.066174 ( 0.009929)| 000000000000028d ffff88eef827bbe8 ffffffff815a542f 000000000000028d
> 2199383.069545 ( 0.003371)| ffffffff810ea142 ffff88eef827bc28 ffffffff8104365c ffff88eefe4006c8
> 2199383.076214 ( 0.006669)| 0000000000000000 00000000000080d0 0000000000000000 0000000000000004
> 2199383.079213 ( 0.002999)| Call Trace:
> 2199383.084084 ( 0.004871)| [<ffffffff815a542f>] dump_stack+0x49/0x62
> 2199383.087283 ( 0.003199)| [<ffffffff810ea142>] ? kmalloc_slab+0x2f/0x89
> 2199383.091415 ( 0.004132)| [<ffffffff8104365c>] warn_slowpath_common+0x77/0x92
> 2199383.095197 ( 0.003782)| [<ffffffff8104368c>] warn_slowpath_null+0x15/0x17
> 2199383.103336 ( 0.008139)| [<ffffffff810ea142>] kmalloc_slab+0x2f/0x89
> 2199383.107082 ( 0.003746)| [<ffffffff8110fd9e>] __kmalloc+0x13/0x16a
> 2199383.112531 ( 0.005449)| [<ffffffffa01a8ed9>] lpfc_pci_probe_one_s4+0x105b/0x1644 [lpfc]
> 2199383.115316 ( 0.002785)| [<ffffffff81302b92>] ? pci_bus_read_config_dword+0x75/0x87
> 2199383.123431 ( 0.008115)| [<ffffffffa01a951f>] lpfc_pci_probe_one+0x5d/0xcb5 [lpfc]
> 2199383.127364 ( 0.003933)| [<ffffffff81497119>] ? dbs_check_cpu+0x168/0x177
> 2199383.136438 ( 0.009074)| [<ffffffff81496fa5>] ? gov_queue_work+0xb4/0xc0
> 2199383.140407 ( 0.003969)| [<ffffffff8130b2a1>] local_pci_probe+0x1e/0x52
> 2199383.143105 ( 0.002698)| [<ffffffff81052c47>] work_for_cpu_fn+0x13/0x1b
> 2199383.147315 ( 0.004210)| [<ffffffff81054965>] process_one_work+0x222/0x35e
> 2199383.151379 ( 0.004064)| [<ffffffff81054e76>] worker_thread+0x3d5/0x46e
> 2199383.159402 ( 0.008023)| [<ffffffff81054aa1>] ? process_one_work+0x35e/0x35e
> 2199383.163097 ( 0.003695)| [<ffffffff810599c6>] kthread+0xc8/0xd2
> 2199383.167476 ( 0.004379)| [<ffffffff810598fe>] ? kthread_freezable_should_stop+0x5b/0x5b
> 2199383.176434 ( 0.008958)| [<ffffffff815a8cac>] ret_from_fork+0x7c/0xb0
> 2199383.180086 ( 0.003652)| [<ffffffff810598fe>] ? kthread_freezable_should_stop+0x5b/0x5b
> 2199383.192333 ( 0.012247)| ehci-pci 0000:00:1a.0: EHCI Host Controller
> -------------------------------------------------------------------->8
>
> The proposed solution was approved by James Smart at Emulex and tested
> on a UV2 machine with 6144 cores. With the fix, the LPFC module loads
> with no unwanted effects on the system.
>
> Signed-off-by: Ian Mitchell <imitchell@xxxxxxx>
> Signed-off-by: Alex Thorlton <athorlton@xxxxxxx>
> Suggested-by: Robert Elliot <elliott@xxxxxx>
> Cc: James Smart <james.smart@xxxxxxxxxxxxx>
> Cc: Dick Kennedy <dick.kennedy@xxxxxxxxxxxxx>
> Cc: James E.J. Bottomley <JBottomley@xxxxxxxx>
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> Signed-off-by: James Smart <james.smart@xxxxxxxxxxxxx>
> ---
> drivers/scsi/lpfc/lpfc_init.c | 6 +-----
> drivers/scsi/lpfc/lpfc_sli4.h | 1 -
> 2 files changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
> index eaf121a..bedbfe6 100644
> --- a/drivers/scsi/lpfc/lpfc_init.c
> +++ b/drivers/scsi/lpfc/lpfc_init.c
> @@ -8678,7 +8678,6 @@ lpfc_sli4_set_affinity(struct lpfc_hba *phba, int vectors)
> #ifdef CONFIG_X86
> struct cpuinfo_x86 *cpuinfo;
> #endif
> - struct cpumask *mask;
> uint8_t chann[LPFC_FCP_IO_CHAN_MAX+1];
>
> /* If there is no mapping, just return */
> @@ -8772,11 +8771,8 @@ found:
> first_cpu = cpu;
>
> /* Now affinitize to the selected CPU */
> - mask = &cpup->maskbits;
> - cpumask_clear(mask);
> - cpumask_set_cpu(cpu, mask);
> i = irq_set_affinity_hint(phba->sli4_hba.msix_entries[idx].
> - vector, mask);
> + vector, get_cpu_mask(cpu));
>
> lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
> "3330 Set Affinity: CPU %d channel %d "
> diff --git a/drivers/scsi/lpfc/lpfc_sli4.h b/drivers/scsi/lpfc/lpfc_sli4.h
> index d1a5b05..1e916e1 100644
> --- a/drivers/scsi/lpfc/lpfc_sli4.h
> +++ b/drivers/scsi/lpfc/lpfc_sli4.h
> @@ -454,7 +454,6 @@ struct lpfc_vector_map_info {
> uint16_t core_id;
> uint16_t irq;
> uint16_t channel_id;
> - struct cpumask maskbits;
> };
> #define LPFC_VECTOR_MAP_EMPTY 0xffff
>
>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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