| Message ID | 20230911112446.1791-1-quic_linyyuan@quicinc.com |
|---|---|
| Headers | show |
| Series | usb: gadget: reduce usb gadget trace event buffer usage | expand |
On 9/11/2023 7:37 PM, Greg Kroah-Hartman wrote: > On Mon, Sep 11, 2023 at 07:24:36PM +0800, Linyu Yuan wrote: >> Some UDC trace event will save usb gadget information, but it will use >> one int size buffer to save one bit information of usb gadget, so more >> than one int buffer to save several bit fields which is not good. >> >> Add one anonymous union have three u32 members which can be used by trace >> event during fast assign stage to reduce trace buffer usage, and add >> related macro to extract bit fields from u32 members for later trace event >> output state usage. >> >> Also move sg_supported and other bit fields into one anonymous struct >> which inside anonymous union and Change bit fields from unsigned to u32 >> type, it will make sure union member have expected u32 size. >> >> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> >> --- >> v2: no change >> >> include/linux/usb/gadget.h | 63 ++++++++++++++++++++++++++------------ >> 1 file changed, 44 insertions(+), 19 deletions(-) >> >> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h >> index 75bda0783395..cdf62e7f34e7 100644 >> --- a/include/linux/usb/gadget.h >> +++ b/include/linux/usb/gadget.h >> @@ -357,6 +357,7 @@ struct usb_gadget_ops { >> * @in_epnum: last used in ep number >> * @mA: last set mA value >> * @otg_caps: OTG capabilities of this gadget. >> + * @dw1: trace event purpose >> * @sg_supported: true if we can handle scatter-gather >> * @is_otg: True if the USB device port uses a Mini-AB jack, so that the >> * gadget driver must provide a USB OTG descriptor. >> @@ -432,25 +433,49 @@ struct usb_gadget { >> unsigned mA; >> struct usb_otg_caps *otg_caps; >> >> - unsigned sg_supported:1; >> - unsigned is_otg:1; >> - unsigned is_a_peripheral:1; >> - unsigned b_hnp_enable:1; >> - unsigned a_hnp_support:1; >> - unsigned a_alt_hnp_support:1; >> - unsigned hnp_polling_support:1; >> - unsigned host_request_flag:1; >> - unsigned quirk_ep_out_aligned_size:1; >> - unsigned quirk_altset_not_supp:1; >> - unsigned quirk_stall_not_supp:1; >> - unsigned quirk_zlp_not_supp:1; >> - unsigned quirk_avoids_skb_reserve:1; >> - unsigned is_selfpowered:1; >> - unsigned deactivated:1; >> - unsigned connected:1; >> - unsigned lpm_capable:1; >> - unsigned wakeup_capable:1; >> - unsigned wakeup_armed:1; >> + union { >> + struct { >> + u32 sg_supported:1; >> + u32 is_otg:1; >> + u32 is_a_peripheral:1; >> + u32 b_hnp_enable:1; >> + u32 a_hnp_support:1; >> + u32 a_alt_hnp_support:1; >> + u32 hnp_polling_support:1; >> + u32 host_request_flag:1; >> + u32 quirk_ep_out_aligned_size:1; >> + u32 quirk_altset_not_supp:1; >> + u32 quirk_stall_not_supp:1; >> + u32 quirk_zlp_not_supp:1; >> + u32 quirk_avoids_skb_reserve:1; >> + u32 is_selfpowered:1; >> + u32 deactivated:1; >> + u32 connected:1; >> + u32 lpm_capable:1; >> + u32 wakeup_capable:1; >> + u32 wakeup_armed:1; >> + } __packed; >> + u32 dw1; >> +#define USB_GADGET_SG_SUPPORTED(n) ((n) & BIT(0)) >> +#define USB_GADGET_IS_OTG(n) ((n) & BIT(1)) >> +#define USB_GADGET_IS_A_PERIPHERAL(n) ((n) & BIT(2)) >> +#define USB_GADGET_B_HNP_ENABLE(n) ((n) & BIT(3)) >> +#define USB_GADGET_A_HNP_SUPPORT(n) ((n) & BIT(4)) >> +#define USB_GADGET_A_ALT_HNP_SUPPORT(n) ((n) & BIT(5)) >> +#define USB_GADGET_HNP_POLLING_SUPPORT(n) ((n) & BIT(6)) >> +#define USB_GADGET_HOST_REQUEST_FLAG(n) ((n) & BIT(7)) >> +#define USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE(n) ((n) & BIT(8)) >> +#define USB_GADGET_QUIRK_ALTSET_NOT_SUPP(n) ((n) & BIT(9)) >> +#define USB_GADGET_QUIRK_STALL_NOT_SUPP(n) ((n) & BIT(10)) >> +#define USB_GADGET_QUIRK_ZLP_NOT_SUPP(n) ((n) & BIT(11)) >> +#define USB_GADGET_QUIRK_AVOIDS_SKB_RESERVE(n) ((n) & BIT(12)) >> +#define USB_GADGET_IS_SELFPOWERED(n) ((n) & BIT(13)) >> +#define USB_GADGET_DEACTIVATED(n) ((n) & BIT(14)) >> +#define USB_GADGET_CONNECTED(n) ((n) & BIT(15)) >> +#define USB_GADGET_LPM_CAPABLE(n) ((n) & BIT(16)) >> +#define USB_GADGET_WAKEUP_CAPABLE(n) ((n) & BIT(17)) >> +#define USB_GADGET_WAKEUP_ARMED(n) ((n) & BIT(18)) > Does this actually work on both types of endian-ness? sorry, only test little endian on ARM64, will consider big endian. > > thanks, > > greg k-h
On 9/11/2023 9:32 PM, Greg Kroah-Hartman wrote: > On Mon, Sep 11, 2023 at 07:24:35PM +0800, Linyu Yuan wrote: >> some trace event use an interger to to save a bit field info of gadget, >> also some trace save endpoint name in string forat, it all can be >> chagned to other way at trace event store phase. >> >> bit field can be replace with a union interger member which include >> multiple bit fields. >> >> ep name stringe can be replace to a interger which contaion number >> and dir info. > Ok, but how much memory did you actually save here? Is the memory saved > only if tracing is enbaled, or it is always? Is there a speed penality > for these changes or is it the same? yes, it is save trace ring buffer only when tracing enabled, as save less data, speed is higher. it is help when enable trace for a long period. for a single trace entry, take struct usb_gadget as example, at worst case, it save (19 dword - 1 dword) / 19dword = 94% buffer. for ep name, it only need 4 bytes/ (4bytes + 9bytes ) = 30%. > > You are doing a lot of code reorginization without any real explaination > of why this is needed, nor proof about it. > > thanks, > > greg k-h