Différences

Ci-dessous, les différences entre deux révisions de la page.

--- tech:memoire_linux [2026/08/03 14:00] – Jean-Baptiste
+++ tech:memoire_linux [2026/09/18 10:19] (Version actuelle) – Jean-Baptiste
@@ Ligne 6: / Ligne 6: @@
 Voir :
 * [[Supervision - sonde Nagios - Memoire Linux]]
+* psacct [[Suivre la conso CPU par utilisateurs]]
 * https://linuxblog.io/free-vs-available-memory-in-linux/
 * https://en.pingcap.com/blog/linux-kernel-vs-memory-fragmentation-2/
@@ Ligne 23: / Ligne 24: @@
 Linux Memory Management :
+* https://fr.wikipedia.org/wiki/Gestionnaire_de_m%C3%A9moire_virtuelle
 * https://lambdafunc.medium.com/linux-memory-management-2c13b5e386f1
 * https://zedas.fr/posts/linux-explained-7-memory-management/
@@ Ligne 176: / Ligne 178: @@
             - memCached // free = total - used
 ~~~
 ## Exemple
+Voir psacct [[Suivre la conso CPU par utilisateurs]]
 ~~~bash
 free -mt
+ps aux --sort=-%mem | head -n 11
 vmstat -SM 45 10
 vmstat -SM -a 45 10
@@ Ligne 190: / Ligne 196: @@
 ps -eo comm,pcpu,pmem,rss --sort rss | tail -n 30 | tac
 ~~~
 ~~~bash
@@ Ligne 291: / Ligne 299: @@
 OOM
+~~~bash
 echo -1000 > /proc/self/oom_score_adj
 cat /proc/<pid>/oom_score
 echo -1000 > /proc/<pid>/oom_score_adj # protect from OOM kill
+~~~
 Or in a specific cgroup, set oom_kill_disable to 1.
+~~~bash
 echo 1000 > /proc/<pid>/oom_score_adj # mark as first target
+~~~
-For systemd services, use OOMScoreAdjust=-1000 in the unit file to protect critical processes.
+For systemd services, use `OOMScoreAdjust=-1000` in the unit file to protect critical processes.
-cgroup_enable=memory swapaccount=1
+`cgroup_enable=memory swapaccount=1`
+~~~
 $ echo $(($(cat /sys/fs/cgroup/memory/memory.max_usage_in_bytes) / 2**20)) MB
 MB
 $ cat /sys/fs/cgroup/memory/memory.stat
+~~~
 ----
@@ Ligne 311: / Ligne 326: @@
 TLB hit TLB miss
+~~~bash
 sudo perf stat -e dTLB-loads,dTLB-load-misses,iTLB-loads,iTLB-load-misses -a sleep 60
 perf list | grep -i tlb
-Slub
+~~~
+Slub
+~~~bash
 slabtop --sort=1
+~~~
+~~~bash
 slabinfo -v
+~~~
 access.redhat.com/
 page_owner=on
-Premature swapping while there is still plenty of pagecache to be reclaimed
-Cgroup v1
-https://access.redhat.com/solutions/6785021
-https://fatdba.com/2025/12/12/when-linux-swaps-away-my-sleep-mysql-rhel8-and-the-curious-case-of-high-swap-usage/
-https://docs.couchbase.com/server/current/install/install-swap-space.html
+## Premature swapping while there is still plenty of pagecache to be reclaimed
-https://support.axway.com/kb/192440/language/en
+Cgroup v1
-https://communities.sas.com/t5/Administration-and-Deployment/Red-Hat-RHEL-8-Release-Swappiness-Algorithm-Setting-Requires/td-p/921008
-https://docs.acceldata.io/odp/documentation/troubleshooting-premature-swapping
+  * https://access.redhat.com/solutions/6785021
+  * https://fatdba.com/2025/12/12/when-linux-swaps-away-my-sleep-mysql-rhel8-and-the-curious-case-of-high-swap-usage/
+  * https://docs.couchbase.com/server/current/install/install-swap-space.html
+  * https://support.axway.com/kb/192440/language/en
+  * https://communities.sas.com/t5/Administration-and-Deployment/Red-Hat-RHEL-8-Release-Swappiness-Algorithm-Setting-Requires/td-p/921008
+  * https://docs.acceldata.io/odp/documentation/troubleshooting-premature-swapping
+  * [Change in swap behavior between RHEL 7 and RHEL 8 kernels](https://access.redhat.com/solutions/7042476)
-Change in swap behavior between RHEL 7 and RHEL 8 kernels
-https://access.redhat.com/solutions/7042476