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From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org, joro@8bytes.org
Cc: 0x7f454c46@gmail.com, Dmitry Safonov <dima@arista.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	iommu@lists.linux-foundation.org
Subject: [PATCHv4 2/2] iommu/vt-d: Limit number of faults to clear in irq handler
Date: Sat, 31 Mar 2018 01:33:12 +0100	[thread overview]
Message-ID: <20180331003312.6390-2-dima@arista.com> (raw)
In-Reply-To: <20180331003312.6390-1-dima@arista.com>

Theoretically, on some machines faults might be generated faster than
they're cleared by CPU. Let's limit the cleaning-loop by number of hw
fault registers.

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 drivers/iommu/dmar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 6c4ea32ee6a9..cf1105111209 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1615,7 +1615,7 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
 irqreturn_t dmar_fault(int irq, void *dev_id)
 {
 	struct intel_iommu *iommu = dev_id;
-	int reg, fault_index;
+	int reg, fault_index, i;
 	u32 fault_status;
 	unsigned long flag;
 	static DEFINE_RATELIMIT_STATE(rs,
@@ -1633,7 +1633,7 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
 
 	fault_index = dma_fsts_fault_record_index(fault_status);
 	reg = cap_fault_reg_offset(iommu->cap);
-	while (1) {
+	for (i = 0; i < cap_num_fault_regs(iommu->cap); i++) {
 		/* Disable printing, simply clear the fault when ratelimited */
 		bool ratelimited = !__ratelimit(&rs);
 		u8 fault_reason;
-- 
2.13.6

  reply	other threads:[~2018-03-31  0:33 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-31  0:33 [PATCHv4 1/2] iommu/vt-d: Ratelimit each dmar fault printing Dmitry Safonov
2018-03-31  0:33 ` Dmitry Safonov [this message]
2018-05-02  6:34   ` [PATCHv4 2/2] iommu/vt-d: Limit number of faults to clear in irq handler Lu Baolu
2018-05-02 12:38     ` Dmitry Safonov
2018-05-02 23:49       ` Lu Baolu
2018-05-03  0:52         ` Dmitry Safonov
2018-05-03  1:32           ` Lu Baolu
2018-05-03  1:59             ` Dmitry Safonov
2018-05-03  2:16               ` Lu Baolu
2018-05-03  2:32                 ` Lu Baolu
2018-05-03  2:34                 ` Dmitry Safonov
2018-05-03  2:44                   ` Lu Baolu
2018-05-02  2:22 ` [PATCHv4 1/2] iommu/vt-d: Ratelimit each dmar fault printing Dmitry Safonov
2018-05-03 12:40   ` Joerg Roedel
2018-05-03 16:12     ` Dmitry Safonov

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