Reduce allocation in Process.GetProcessesByName #68705

stephentoub · 2022-04-29T16:26:20Z

GetProcessesByName is loading all of the information for every process found, even if it'll immediately be thrown away because the name doesn't match.

[Benchmark]
public void GetProcessesByName()
{
    foreach (Process p in Process.GetProcessesByName("dotnet.exe"))
        p.Dispose();
}

Method	Toolchain	Mean	Ratio	Allocated	Alloc Ratio
GetProcessesByName	\main\corerun.exe	4.415 ms	1.00	622.43 KB	1.000
GetProcessesByName	\pr\corerun.exe	4.066 ms	0.91	2.14 KB	0.003

ghost · 2022-04-29T16:26:26Z

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Issue Details

GetProcessesByName is loading all of the information for every process found, even if it'll immediately be thrown away because the name doesn't match.

[Benchmark]
public void GetProcessesByName()
{
    foreach (Process p in Process.GetProcessesByName("dotnet.exe"))
        p.Dispose();
}

Method	Toolchain	Mean	Ratio	Allocated	Alloc Ratio
GetProcessesByName	\main\corerun.exe	4.415 ms	1.00	622.43 KB	1.000
GetProcessesByName	\pr\corerun.exe	4.066 ms	0.91	2.14 KB	0.003

Author:	stephentoub
Assignees:	stephentoub
Labels:	`area-System.Diagnostics.Process`
Milestone:	-

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.FreeBSD.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.UnknownUnix.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.Win32.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.Windows.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.Win32.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.Linux.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.OSX.cs

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.BSD.cs

GetProcessesByName is loading all of the information for every process found, even if it'll immediately be thrown away because the name doesn't match.

stephentoub · 2022-05-01T18:18:03Z

Note this also fixed the unreported issue on Linux/macOS that passing null or empty string to GetProcessesByName shouldn't filter anything out but was filtering everything out.

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Linux.cs

DrewScoggins · 2022-05-05T16:48:26Z

Improvement: dotnet/perf-autofiling-issues#5077

stephentoub requested a review from adamsitnik April 29, 2022 16:26

ghost added the area-System.Diagnostics.Process label Apr 29, 2022

ghost assigned stephentoub Apr 29, 2022

stephentoub added this to the 7.0.0 milestone Apr 29, 2022

stephentoub added the tenet-performance Performance related issue label Apr 29, 2022