From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org,
"K. Y. Srinivasan" <kys@microsoft.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Wei Liu" <wei.liu@kernel.org>,
"Dexuan Cui" <decui@microsoft.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Rob Herring" <robh@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org
Cc: Yury Norov <yury.norov@gmail.com>, Jan Kara <jack@suse.cz>,
Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>,
Matthew Wilcox <willy@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>,
Alexey Klimov <klimov.linux@gmail.com>
Subject: [PATCH 14/34] PCI: hv: switch hv_get_dom_num() to use atomic find_bit()
Date: Sat, 18 Nov 2023 07:50:45 -0800 [thread overview]
Message-ID: <20231118155105.25678-15-yury.norov@gmail.com> (raw)
In-Reply-To: <20231118155105.25678-1-yury.norov@gmail.com>
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
next prev parent reply other threads:[~2023-11-18 15:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-18 15:50 [PATCH 00/34] biops: add atomig find_bit() operations Yury Norov
2023-11-18 15:50 ` [PATCH 01/34] lib/find: add atomic find_bit() primitives Yury Norov
2023-11-18 16:23 ` Bart Van Assche
2023-11-18 15:50 ` Yury Norov [this message]
2023-11-18 17:59 ` [PATCH 14/34] PCI: hv: switch hv_get_dom_num() to use atomic find_bit() Michael Kelley
2023-11-18 16:18 ` [PATCH 00/34] biops: add atomig find_bit() operations Bart Van Assche
2023-11-18 19:06 ` Sergey Shtylyov
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