Bug 179086
| Summary: | fork() slow when shm attached to process | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 4 | Reporter: | Bastien Nocera <bnocera> |
| Component: | kernel | Assignee: | Larry Woodman <lwoodman> |
| Status: | CLOSED DUPLICATE | QA Contact: | Brian Brock <bbrock> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 4.0 | CC: | csnook, jbaron |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-04-19 19:22:24 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 170416 | ||
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Description
Bastien Nocera
2006-01-27 09:45:25 UTC
Support has received calls from customers of Ontario Systems, who recommend running kernels with the lazy fork patch. For apps that use large shared memory spaces and fork to service each request, the performance impact can be orders of magnitude. The downside is that it's possible to have an OOM condition when the app accesses a new part of the shared segment and the kernel needs to copy a PTE, a very long time after the fork itself, thus hiding the cause. If we implement this, we should at least add an appropriate error message in oom-killer as well. |