Skip to content

Cap storage hw queue count to 4 #40975

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
chemwolf6922 wants to merge 4 commits into
base: master
Choose a base branch
from
+16 −8
Open

Cap storage hw queue count to 4 #40975

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
a707324
cap storage hw queue count to 4
chemwolf6922 Jul 2, 2026
cf79f9e
resolve comments
chemwolf6922 Jul 2, 2026
d4b10fd
apply change to both wslc and wsl
chemwolf6922 Jul 3, 2026
cb2d460
move nr_cpus to common kernel cmd
Jul 7, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 13 additions & 1 deletion src/windows/common/helpers.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,8 @@ using wsl::windows::common::helpers::LaunchWslRelayFlags;
constexpr auto c_WslSupportInterfaceKey = L"Software\\Classes\\Interface\\{46f3c96d-ffa3-42f0-b052-52f5e7ecbb08}";
constexpr auto c_WslSupportInterfaceName = L"IWslSupport";

constexpr ULONG c_MaxStorageHwQueues = 4;

namespace {

class ProcessLauncher
Expand Down Expand Up @@ -762,8 +764,12 @@ try
}
CATCH_LOG()

void wsl::windows::common::helpers::AppendCommonKernelCommandLine(_Inout_ std::wstring& kernelCmdLine, _In_ int pageReportingOrder, _In_ ULONG64 swiotlbSizeBytes)
void wsl::windows::common::helpers::AppendCommonKernelCommandLine(
_Inout_ std::wstring& kernelCmdLine, _In_ int pageReportingOrder, _In_ ULONG64 swiotlbSizeBytes, _In_ ULONG cpuCount)
{
// Set number of processors.
kernelCmdLine += std::format(L" nr_cpus={}", cpuCount);

// Enable timesync workaround to sync on resume from sleep in modern standby.
kernelCmdLine += L" hv_utils.timesync_implicit=1";

Expand All @@ -778,6 +784,12 @@ void wsl::windows::common::helpers::AppendCommonKernelCommandLine(_Inout_ std::w
{
kernelCmdLine += std::format(L" swiotlb=force hv_pci_swiotlb={}", swiotlbSizeBytes);
}

// Cap the storage hw queue count. Default is CPU count.
if (cpuCount > c_MaxStorageHwQueues)
{
kernelCmdLine += std::format(L" hv_storvsc.storvsc_max_hw_queues={}", c_MaxStorageHwQueues);
}
}

UINT64 wsl::windows::common::helpers::ComputeDefaultSwiotlbConfig(_In_ UINT64 memoryBytes)
Expand Down
2 changes: 1 addition & 1 deletion src/windows/common/helpers.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -205,7 +205,7 @@ bool TryAttachConsole();

void RegisterWithDcat(_In_ bool IncludeVersionNumber = true);

void AppendCommonKernelCommandLine(_Inout_ std::wstring& kernelCmdLine, _In_ int pageReportingOrder, _In_ ULONG64 swiotlbSizeBytes);
void AppendCommonKernelCommandLine(_Inout_ std::wstring& kernelCmdLine, _In_ int pageReportingOrder, _In_ ULONG64 swiotlbSizeBytes, _In_ ULONG cpuCount);

UINT64 ComputeDefaultSwiotlbConfig(_In_ UINT64 memoryBytes);

Expand Down
3 changes: 1 addition & 2 deletions src/windows/service/exe/HcsVirtualMachine.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -166,8 +166,7 @@ HcsVirtualMachine::HcsVirtualMachine(_In_ const WSLCSessionSettings* Settings)

// Initialize kernel command line.
std::wstring kernelCmdLine = L"initrd=\\" LXSS_VM_MODE_INITRD_NAME L" " TEXT(WSLC_ROOT_INIT_ENV) L"=1 panic=-1";
kernelCmdLine += std::format(L" nr_cpus={}", Settings->CpuCount);
helpers::AppendCommonKernelCommandLine(kernelCmdLine, pageReportingOrder, swiotlbSizeBytes);
helpers::AppendCommonKernelCommandLine(kernelCmdLine, pageReportingOrder, swiotlbSizeBytes, Settings->CpuCount);

// Setup dmesg collector with optional DmesgOutput handle.
// TODO: move dmesg collector to user session process.
Expand Down
5 changes: 1 addition & 4 deletions src/windows/service/exe/WslCoreVm.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1575,11 +1575,8 @@ std::wstring WslCoreVm::GenerateConfigJson()
// Initialize kernel command line.
std::wstring kernelCmdLine = L"initrd=\\" LXSS_VM_MODE_INITRD_NAME L" " TEXT(WSL_ROOT_INIT_ENV) L"=1 panic=-1";

// Set number of processors.
kernelCmdLine += std::format(L" nr_cpus={}", m_vmConfig.ProcessorCount);

// Append common kernel parameters shared between WSL2 and WSLC.
helpers::AppendCommonKernelCommandLine(kernelCmdLine, m_pageReportingOrder, m_vmConfig.SwiotlbSizeBytes);
helpers::AppendCommonKernelCommandLine(kernelCmdLine, m_pageReportingOrder, m_vmConfig.SwiotlbSizeBytes, m_vmConfig.ProcessorCount);

if (m_vmConfig.EnableVirtio && helpers::IsVirtioSerialConsoleSupported())
{
Expand Down