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Commit 4b202b71 authored by Jon Derrick's avatar Jon Derrick Committed by Bjorn Helgaas
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PCI/AER: Avoid memory allocation in interrupt handling path 



When handling AER events, we previously allocated a struct aer_err_info,
processed the error, and freed the struct.  But aer_isr_one_error() is
serialized by rpc_mutex, so we never need more than one copy of the struct,
and the struct is only about 70 bytes, so we're not saving much by
allocating it dynamically.

Embed a struct aer_err_info directly in struct aer_rpc, which is allocated
at probe-time by aer_probe().

[bhelgaas: changelog]
Suggested-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarJon Derrick <jonathan.derrick@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 2458d66b

drivers/pci/pcie/aer/aerdrv.h

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ struct aer_rpc { 
	struct pcie_device *rpd;	/* Root Port device */

	struct work_struct dpc_handler;

	struct aer_err_source e_sources[AER_ERROR_SOURCES_MAX];

	struct aer_err_info e_info;

	unsigned short prod_idx;	/* Error Producer Index */

	unsigned short cons_idx;	/* Error Consumer Index */

	int isr;

drivers/pci/pcie/aer/aerdrv_core.c

+2 −11
Original line number Diff line number Diff line
@@ -711,15 +711,8 @@ static inline void aer_process_err_devices(struct pcie_device *p_device, 
static void aer_isr_one_error(struct pcie_device *p_device,

		struct aer_err_source *e_src)

{

	struct aer_err_info *e_info;



	/* struct aer_err_info might be big, so we allocate it with slab */

	e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL);

	if (!e_info) {

		dev_printk(KERN_DEBUG, &p_device->port->dev,

			"Can't allocate mem when processing AER errors\n");

		return;

	}

	struct aer_rpc *rpc = get_service_data(p_device);

	struct aer_err_info *e_info = &rpc->e_info;



	/*

	 * There is a possibility that both correctable error and
@@ -758,8 +751,6 @@ static void aer_isr_one_error(struct pcie_device *p_device, 
		if (find_source_device(p_device->port, e_info))

			aer_process_err_devices(p_device, e_info);

	}



	kfree(e_info);

}



/**