Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →SELinux and AppArmor are Linux Security Modules (LSMs) that enforce mandatory access control (MAC); grsecurity is a hardened-kernel patch set that adds protections beyond MAC. Choose SELinux for labeled, system-wide policy and strong process separation, AppArmor for application-focused path-based profiles—especially on Ubuntu—or grsecurity when kernel hardening is central and you can maintain patched kernels or obtain commercial support.
How the three options differ
| Option | What it is | Policy or protection model | Typical operational fit |
|---|---|---|---|
| SELinux | A Linux Security Module that implements MAC, built into the kernel, according to Red Hat. | Uses labeled security contexts and policy domains to control interactions among processes, files, sockets, and other objects. | System-wide policy and process separation; deeply integrated into Red Hat Enterprise Linux (RHEL). |
| AppArmor | A MAC-style Linux kernel security extension, according to the Linux kernel documentation. | Uses task-centered, application-focused profiles that are path-based. An application without a profile remains unconfined under ordinary discretionary access control (DAC) permissions. | Application confinement with readable profiles; a core part of Ubuntu security and Ubuntu Core snap confinement. |
| grsecurity | A hardened Linux kernel patch set, not a conventional standalone MAC policy module. | Adds kernel hardening and exploit-mitigation features beyond MAC. Customers receive source patches to apply to supported kernels. | Organizations prioritizing kernel hardening that can build and maintain patched kernels or purchase support. |
The upstream SELinux project describes SELinux as “flexible Mandatory Access Control (MAC) for Linux.” The Linux kernel documentation calls AppArmor a “MAC style security extension for the Linux kernel.” Those labels identify the shared goal—restricting access beyond ordinary DAC—but the policy models and deployment work differ.
How SELinux and AppArmor enforce policy
SELinux: labels and policy domains
SELinux assigns security contexts to system objects and uses policy domains to govern what processes can do. The model applies across processes and objects such as files and sockets, so policy can express system-wide relationships rather than only attaching a profile to a particular application.
Red Hat documents three states reported by getenforce: Enforcing, Permissive, and Disabled. The active policy controls how users and processes interact with files and devices. This makes SELinux a fit when a deployment needs deliberate separation among users or process domains, but it also means policy understanding and troubleshooting must account for labels and domains.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problems#1 Best Overall
AppArmor: application profiles and paths
AppArmor associates task-centered profiles with applications and uses paths in those profiles to describe permitted access. Its application-oriented model can make confinement rules easier to read and manage for a defined set of programs. The trade-off is that an unprofiled application does not automatically receive an AppArmor confinement boundary: it continues under the system’s normal DAC permissions.
The Linux kernel documentation describes AppArmor profiles as loaded from user space. Ubuntu identifies AppArmor as central to Ubuntu and Ubuntu Core snap confinement, making the distribution’s existing profiles and tooling important to deployment effort.
Rank #2
grsecurity: kernel hardening plus patch maintenance
grsecurity changes the kernel through source patches that customers apply, configure, compile, and install. Its purpose is broader than a conventional MAC policy module: it includes exploit mitigation and kernel-hardening features. The official grsecurity FAQ states that supported kernels are Linux 6.6 and 6.18; the project supports 6.6 through at least the end of 2026 and 6.18 through at least the end of 2028.
Those support windows are not equivalent to installing a distribution’s standard security package. The organization must handle patched-kernel configuration, building, installation, and ongoing maintenance, or use grsecurity’s commercial support, which includes stable patch access, RBAC policy development, kernel maintenance, configuration auditing, and general hardening.
Recommended Free Tools
Choosing by distribution and operational needs
- Choose SELinux when labeled, system-wide policy and separation of users or process domains are priorities, particularly on enterprise distributions where policy tools and compliance integration matter. RHEL is deeply integrated with SELinux.
- Choose AppArmor when application-level path profiles, readable rules, and Ubuntu integration are the practical fit. Its established role in Ubuntu and Ubuntu Core can reduce work compared with migrating to a different policy model.
- Consider grsecurity when the threat model gives high priority to kernel exploit mitigation and hardened container or multi-tenant isolation, and the team can maintain patched kernels or purchase support.
Distribution defaults are an operational constraint, not a minor preference. Switching the default LSM can require policy migration, relabeling or profile work, and incident-response retraining. Before choosing a different default, account for the existing system’s policy assets and the team’s ability to investigate denials and maintain the resulting configuration.
Policy work, troubleshooting, and compliance
These options require different troubleshooting habits. SELinux investigations center on security contexts, policy domains, and the policy governing an interaction. AppArmor investigations center on whether the application has a profile and what that path-based profile permits. With grsecurity, the work also includes kernel configuration, patch application, and kernel lifecycle management.
Tooling and compliance expectations should be assessed in the distribution and environment where the controls will run. SELinux is deeply integrated into RHEL, and the selection guidance for enterprise distributions favors it when policy tooling and compliance integration are priorities. AppArmor’s Ubuntu integration is a deployment advantage there. The available grsecurity support description includes configuration auditing, but does not establish a specific compliance certification or guarantee that a deployment meets a particular standard.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Performance, compatibility, and support trade-offs
The available project and distribution descriptions establish these tools’ models and operational requirements, but do not provide comparable performance measurements. There is no sound basis here for claiming that one is faster. Performance and compatibility should be validated against the actual kernel, distribution, workloads, and policy or patch configuration before a production rollout.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Support also differs in form. SELinux and AppArmor are integrated into their respective distribution ecosystems, notably RHEL and Ubuntu. grsecurity offers customer-only access to stable patches and commercial support for kernel and policy work. Its supported kernel versions and minimum support horizons are set by the grsecurity FAQ: Linux 6.6 through at least the end of 2026, and Linux 6.18 through at least the end of 2028.
Quick Recap
A practical selection checklist
- Start with the distribution. Identify the default LSM, existing policy or profile coverage, and the support model your organization already uses.
- Define what must be confined. Use SELinux when you need labeled policy across processes and objects; use AppArmor when application-focused path profiles address the need; consider grsecurity when broader kernel hardening is the priority.
- Include unconfined workloads in the threat model. With AppArmor, determine which applications lack profiles and therefore remain under ordinary DAC permissions.
- Estimate ongoing operational work. Account for policy authoring and denial investigation for SELinux or AppArmor, and for patching, configuring, compiling, installing, and maintaining kernels with grsecurity.
- Test compatibility and response procedures. Validate the chosen setup with the target workloads and train responders to diagnose the relevant policy or kernel issues before relying on it in production.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
