| Message ID | 20231118155105.25678-15-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | biops: add atomig find_bit() operations | expand |
From: Yury Norov <yury.norov@gmail.com> Sent: Saturday, November 18, 2023 7:51 AM > > The function traverses bitmap with for_each_clear_bit() just to allocate > a bit atomically. We can do it better with a dedicated find_and_set_bit(). > > Signed-off-by: Yury Norov <yury.norov@gmail.com> > --- > drivers/pci/controller/pci-hyperv.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci- > hyperv.c > index 30c7dfeccb16..033b1fb7f4eb 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -3605,12 +3605,9 @@ static u16 hv_get_dom_num(u16 dom) > if (test_and_set_bit(dom, hvpci_dom_map) == 0) > return dom; > > - for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) { > - if (test_and_set_bit(i, hvpci_dom_map) == 0) > - return i; > - } > + i = find_and_set_bit(hvpci_dom_map, HVPCI_DOM_MAP_SIZE); > > - return HVPCI_DOM_INVALID; > + return i < HVPCI_DOM_MAP_SIZE ? i : HVPCI_DOM_INVALID; > } > > /** > -- > 2.39.2 Reviewed-by: Michael Kelley <mhklinux@outlook.com>
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 30c7dfeccb16..033b1fb7f4eb 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -3605,12 +3605,9 @@ static u16 hv_get_dom_num(u16 dom) if (test_and_set_bit(dom, hvpci_dom_map) == 0) return dom; - for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) { - if (test_and_set_bit(i, hvpci_dom_map) == 0) - return i; - } + i = find_and_set_bit(hvpci_dom_map, HVPCI_DOM_MAP_SIZE); - return HVPCI_DOM_INVALID; + return i < HVPCI_DOM_MAP_SIZE ? i : HVPCI_DOM_INVALID; } /**
The function traverses bitmap with for_each_clear_bit() just to allocate a bit atomically. We can do it better with a dedicated find_and_set_bit(). Signed-off-by: Yury Norov <yury.norov@gmail.com> --- drivers/pci/controller/pci-hyperv.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)