Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768AbdIFJOP (ORCPT ); Wed, 6 Sep 2017 05:14:15 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:5556 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436AbdIFJMk (ORCPT ); Wed, 6 Sep 2017 05:12:40 -0400 From: Jason Yan To: , CC: , , , , , , , , , , , , , Ewan Milne , Tomas Henzl Subject: [PATCH v4 06/11] libsas: shut down the PHY if events reached the threshold Date: Wed, 6 Sep 2017 17:15:09 +0800 Message-ID: <1504689314-20072-7-git-send-email-yanaijie@huawei.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1504689314-20072-1-git-send-email-yanaijie@huawei.com> References: <1504689314-20072-1-git-send-email-yanaijie@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.59AFBC00.00D7,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: cde5659c590c67c2fed7cf50fb4dda95 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5478 Lines: 177 If the PHY burst too many events, we will alloc a lot of events for the worker. This may leads to memory exhaustion. Dan Williams suggested to shut down the PHY if the events reached the threshold, because in this case the PHY may have gone into some erroneous state. Users can re-enable the PHY by sysfs if they want. We cannot use the fixed memory pool because if we run out of events, the shut down event and loss of signal event will lost too. The events still need to be allocated and processed in this case. Suggested-by: Dan Williams Signed-off-by: Jason Yan CC: John Garry CC: Johannes Thumshirn CC: Ewan Milne CC: Christoph Hellwig CC: Tomas Henzl --- drivers/scsi/libsas/sas_init.c | 21 ++++++++++++++++++++- drivers/scsi/libsas/sas_phy.c | 31 ++++++++++++++++++++++++++++++- include/scsi/libsas.h | 6 ++++++ 3 files changed, 56 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c index 85c278a..b1e03d5 100644 --- a/drivers/scsi/libsas/sas_init.c +++ b/drivers/scsi/libsas/sas_init.c @@ -122,6 +122,8 @@ int sas_register_ha(struct sas_ha_struct *sas_ha) INIT_LIST_HEAD(&sas_ha->defer_q); INIT_LIST_HEAD(&sas_ha->eh_dev_q); + sas_ha->event_thres = SAS_PHY_SHUTDOWN_THRES; + error = sas_register_phys(sas_ha); if (error) { printk(KERN_NOTICE "couldn't register sas phys:%d\n", error); @@ -556,14 +558,31 @@ EXPORT_SYMBOL_GPL(sas_domain_attach_transport); struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy) { + struct asd_sas_event *event; gfp_t flags = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL; - return kmem_cache_zalloc(sas_event_cache, flags); + event = kmem_cache_zalloc(sas_event_cache, flags); + if (!event) + return NULL; + + atomic_inc(&phy->event_nr); + if (atomic_read(&phy->event_nr) > phy->ha->event_thres && + !phy->in_shutdown) { + phy->in_shutdown = 1; + sas_printk("The phy%02d bursting events, shut it down.\n", + phy->id); + sas_notify_phy_event(phy, PHYE_SHUTDOWN); + } + + return event; } void sas_free_event(struct asd_sas_event *event) { + struct asd_sas_phy *phy = event->phy; + kmem_cache_free(sas_event_cache, event); + atomic_dec(&phy->event_nr); } /* ---------- SAS Class register/unregister ---------- */ diff --git a/drivers/scsi/libsas/sas_phy.c b/drivers/scsi/libsas/sas_phy.c index 59f8292..3df1eec 100644 --- a/drivers/scsi/libsas/sas_phy.c +++ b/drivers/scsi/libsas/sas_phy.c @@ -35,6 +35,7 @@ static void sas_phye_loss_of_signal(struct work_struct *work) struct asd_sas_event *ev = to_asd_sas_event(work); struct asd_sas_phy *phy = ev->phy; + phy->in_shutdown = 0; phy->error = 0; sas_deform_port(phy, 1); } @@ -44,6 +45,7 @@ static void sas_phye_oob_done(struct work_struct *work) struct asd_sas_event *ev = to_asd_sas_event(work); struct asd_sas_phy *phy = ev->phy; + phy->in_shutdown = 0; phy->error = 0; } @@ -105,6 +107,32 @@ static void sas_phye_resume_timeout(struct work_struct *work) } +static void sas_phye_shutdown(struct work_struct *work) +{ + struct asd_sas_event *ev = to_asd_sas_event(work); + struct asd_sas_phy *phy = ev->phy; + struct sas_ha_struct *sas_ha = phy->ha; + struct sas_internal *i = + to_sas_internal(sas_ha->core.shost->transportt); + + if (phy->enabled && i->dft->lldd_control_phy) { + int ret; + + phy->error = 0; + phy->enabled = 0; + ret = i->dft->lldd_control_phy(phy, PHY_FUNC_DISABLE, NULL); + if (ret) + sas_printk("lldd disable phy%02d returned %d\n", + phy->id, ret); + + } else if (!i->dft->lldd_control_phy) + sas_printk("lldd does not support phy%02d control\n", phy->id); + else + sas_printk("phy%02d is not enabled, cannot shutdown\n", + phy->id); + +} + /* ---------- Phy class registration ---------- */ int sas_register_phys(struct sas_ha_struct *sas_ha) @@ -116,6 +144,7 @@ int sas_register_phys(struct sas_ha_struct *sas_ha) struct asd_sas_phy *phy = sas_ha->sas_phy[i]; phy->error = 0; + atomic_set(&phy->event_nr, 0); INIT_LIST_HEAD(&phy->port_phy_el); phy->port = NULL; @@ -151,5 +180,5 @@ const work_func_t sas_phy_event_fns[PHY_NUM_EVENTS] = { [PHYE_OOB_ERROR] = sas_phye_oob_error, [PHYE_SPINUP_HOLD] = sas_phye_spinup_hold, [PHYE_RESUME_TIMEOUT] = sas_phye_resume_timeout, - + [PHYE_SHUTDOWN] = sas_phye_shutdown, }; diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h index c80321b..2fa0b13 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -75,6 +75,7 @@ enum phy_event { PHYE_OOB_ERROR, PHYE_SPINUP_HOLD, /* hot plug SATA, no COMWAKE sent */ PHYE_RESUME_TIMEOUT, + PHYE_SHUTDOWN, PHY_NUM_EVENTS, }; @@ -310,12 +311,15 @@ static inline void INIT_SAS_EVENT(struct asd_sas_event *ev, void (*fn)(struct wo ev->event = event; } +#define SAS_PHY_SHUTDOWN_THRES 1024 /* The phy pretty much is controlled by the LLDD. * The class only reads those fields. */ struct asd_sas_phy { /* private: */ + atomic_t event_nr; + int in_shutdown; int error; int suspended; @@ -403,6 +407,8 @@ struct sas_ha_struct { struct list_head eh_done_q; /* complete via scsi_eh_flush_done_q */ struct list_head eh_ata_q; /* scmds to promote from sas to ata eh */ + + int event_thres; }; #define SHOST_TO_SAS_HA(_shost) (*(struct sas_ha_struct **)(_shost)->hostdata) -- 2.5.0