Bug 247767
| Summary: | megaraid_sas ioctls fail under load | ||||||
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| Product: | Red Hat Enterprise Linux 4 | Reporter: | Bryn M. Reeves <bmr> | ||||
| Component: | kernel | Assignee: | Bryn M. Reeves <bmr> | ||||
| Status: | CLOSED DUPLICATE | QA Contact: | Martin Jenner <mjenner> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | medium | ||||||
| Version: | 4.5 | CC: | andriusb, publicmailbox, suran.kularatna, tao | ||||
| 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: | 2008-02-06 18:08:29 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: | 422551, 430698 | ||||||
| Attachments: |
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Created attachment 158935 [details]
re-diff of upstream patch for RHEL4
This problem is addressed with the updated driver being tracked in bug 312061. *** This bug has been marked as a duplicate of 312061 *** where is the patch for this? what is thenumber? Attached in comment #4 (a backport of the git commit given in comment #0). This bug is a duplicate of bug 312061, but that bug is not viewable by me. Why is it being kept a secret? Ben - this issue was resolved in RHEL 4.7. Please upgrade to RHEL 4.7, else file a support ticket. Bug 312061 contains partner-NDA confidential information in it. |
Description of problem: The megaraid_sas driver uses pci_alloc_consistent to allocate an array of buffers to copy user arguments into within the ioctl path. This can fail under heavy load leading to messages like: megasas: Failed to alloc kernel SGL buffer for IOCTL Upstream fixed this here: commit 9f35fa8a14e6216a859e2dfbe50ade497f9603ef Author: Sumant Patro <sumantp> Date: Wed Feb 14 12:55:45 2007 -0800 [SCSI] megaraid_sas: replace pci_alloc_consitent with dma_alloc_coherent in ioctl path Replaced pci_alloc_consistent with dma_alloc_coherent from the ioctl path. This is to avoid situations where ioctl fails for lack of memory (when system under heavy stress). Signed-off-by: Sumant Patro <sumant.patro> Signed-off-by: James Bottomley <James.Bottomley> Appearing in dmesg. Version-Release number of selected component (if applicable): kernel-2.6.9-55.EL How reproducible: Moderate; problem was observed during pre-production stress testing of boxes using megaraid_sas as the primary storage. Steps to Reproduce: 1. Configure a system with megaraid_sas providing storage 2. Create memory pressure on the system while something is attempting ioctl commands on the megaraid Actual results: Appearance of: "megasas: Failed to alloc kernel SGL buffer for IOCTL" in dmesg. Expected results: Megaraid_sas ioctls succeed.