> Source: [sk113834](https://support.checkpoint.com/results/sk/sk113834)

# sk113834 - Unused CPU cores after changing CoreXL Affinity settings

| Property | Value |
|----------|-------|
| Solution ID | sk113834 |
| Date Created | 2016-10-10 |
| Last Modified | 2023-02-13 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |
| OS | Gaia |

## Symptoms

- After configuring CoreXL Affinity with the "`fw ctl affinity`" command, some CPU cores are left available and they are not automatically used by Multi-Queue or SecureXL.

## Cause

CoreXL Affinity settings made with the "`fw ctl affinity`" command are applied immediately and do not require reboot.

Changes made in Multi-Queue configuration require a reboot.

## Solution

Changing the User Space process affinity does not affect the Multi-Queue resources. If one of the CPU cores is not allocated to any process based on the affinity arguments in the syntax, it becomes unused and is not automatically allocated to Multi-Queue.

**The administrator must reboot the Security Gateway to recalculate the distribution of CPU cores. This allocates the unassigned CPU cores to Multi-Queue.**

*Example*:

1. Configure CoreXL to work with 18 CPU cores out of 20.

2. CPU cores 0-1 are allocated to Multi-Queue.

3. CPU cores 2-19 are allocated to CoreXL Firewall instances.

4. Configure CoreXL to work on CPU cores 4-19 with this command:

   *fw ctl affinity -s -d -fwkall 16*
5. The affinity list (*fw ctl affinity -l -a*) show that CoreXL Firewall instances moved to CPU cores 4-19, and the Multi-Queue still works on CPU cores 0-1. This leaves the CPU core 2 and the CPU core 3 unused.

6. Reboot the Security Gateway.

7. The affinity list (*fw ctl affinity -l -a*) shows that the CPU core 2 and CPU core 3 is allocated to Multi-Queue.

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