| Message ID | 1649299514-64014-1-git-send-email-quic_wat@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: hcd: add a flag for whether using shared_hcd priv | expand |
On Thu, Apr 07, 2022 at 10:45:14AM +0800, Tao Wang wrote: > The shared_hcd->hcd_priv is not used in xhci, so not > need to malloc hcd priv memory for shared_hcd. What is the problem with allocating that memory? Do you have systems with thousands of USB host controllers where this memory is wasted? > This change add a shared_hcd_no_priv flag to indicate > if shared_hcd use priv, and set the flag of xhci to 1. 1 is not a boolean :( > > Signed-off-by: Tao Wang <quic_wat@quicinc.com> > --- > drivers/usb/core/hcd.c | 6 +++++- > drivers/usb/host/xhci-plat.c | 1 + > include/linux/usb/hcd.h | 1 + > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c > index 99908d8..f339c3e 100644 > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -2419,7 +2419,11 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, > { > struct usb_hcd *hcd; > > - hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL); > + if (primary_hcd && driver->shared_hcd_no_priv) > + hcd = kzalloc(sizeof(*hcd), GFP_KERNEL); > + else > + hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL); > + > if (!hcd) > return NULL; > if (primary_hcd == NULL) { > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c > index 21280a6..223e508 100644 > --- a/drivers/usb/host/xhci-plat.c > +++ b/drivers/usb/host/xhci-plat.c > @@ -236,6 +236,7 @@ static int xhci_plat_probe(struct platform_device *pdev) > return -ENODEV; > > driver = &xhci_plat_hc_driver; > + driver->shared_hcd_no_priv = 1; true? > > irq = platform_get_irq(pdev, 0); > if (irq < 0) > diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h > index 2ffafbd..03ac312 100644 > --- a/include/linux/usb/hcd.h > +++ b/include/linux/usb/hcd.h > @@ -256,6 +256,7 @@ struct hc_driver { > const char *description; /* "ehci-hcd" etc */ > const char *product_desc; /* product/vendor string */ > size_t hcd_priv_size; /* size of private data */ > + bool shared_hcd_no_priv; /* 0 use priv, 1 not use priv*/ Did you check to see how much extra padding you just added to the structure? When writing a change to try to save memory, do not cause extra memory to be wasted for everyone. thanks, greg k-h
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 99908d8..f339c3e 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -2419,7 +2419,11 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver, { struct usb_hcd *hcd; - hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL); + if (primary_hcd && driver->shared_hcd_no_priv) + hcd = kzalloc(sizeof(*hcd), GFP_KERNEL); + else + hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL); + if (!hcd) return NULL; if (primary_hcd == NULL) { diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 21280a6..223e508 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -236,6 +236,7 @@ static int xhci_plat_probe(struct platform_device *pdev) return -ENODEV; driver = &xhci_plat_hc_driver; + driver->shared_hcd_no_priv = 1; irq = platform_get_irq(pdev, 0); if (irq < 0) diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index 2ffafbd..03ac312 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -256,6 +256,7 @@ struct hc_driver { const char *description; /* "ehci-hcd" etc */ const char *product_desc; /* product/vendor string */ size_t hcd_priv_size; /* size of private data */ + bool shared_hcd_no_priv; /* 0 use priv, 1 not use priv*/ /* irq handler */ irqreturn_t (*irq) (struct usb_hcd *hcd);
The shared_hcd->hcd_priv is not used in xhci, so not need to malloc hcd priv memory for shared_hcd. This change add a shared_hcd_no_priv flag to indicate if shared_hcd use priv, and set the flag of xhci to 1. Signed-off-by: Tao Wang <quic_wat@quicinc.com> --- drivers/usb/core/hcd.c | 6 +++++- drivers/usb/host/xhci-plat.c | 1 + include/linux/usb/hcd.h | 1 + 3 files changed, 7 insertions(+), 1 deletion(-)