[PATCH] temporarily disable swap token on memory pressure
Some users (hi Zwane) have seen a problem when running a workload that eats nearly all of physical memory - th system does an OOM kill, even when there is still a lot of swap free. The problem appears to be a very big task that is holding the swap token, and the VM has a very hard time finding any other page in the system that is swappable. Instead of ignoring the swap token when sc->priority reaches 0, we could simply take the swap token away from the memory hog and make sure we don't give it back to the memory hog for a few seconds. This patch resolves the problem Zwane ran into. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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committed by
Linus Torvalds

parent
a93a117eaa
commit
f7b7fd8f3e
10
mm/thrash.c
10
mm/thrash.c
@@ -57,14 +57,17 @@ void grab_swap_token(void)
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/* We have the token. Let others know we still need it. */
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if (has_swap_token(current->mm)) {
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current->mm->recent_pagein = 1;
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if (unlikely(!swap_token_default_timeout))
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disable_swap_token();
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return;
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}
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if (time_after(jiffies, swap_token_check)) {
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/* Can't get swapout protection if we exceed our RSS limit. */
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// if (current->mm->rss > current->mm->rlimit_rss)
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// return;
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if (!swap_token_default_timeout) {
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swap_token_check = jiffies + SWAP_TOKEN_CHECK_INTERVAL;
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return;
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}
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/* ... or if we recently held the token. */
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if (time_before(jiffies, current->mm->swap_token_time))
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@@ -95,6 +98,7 @@ void __put_swap_token(struct mm_struct *mm)
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{
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spin_lock(&swap_token_lock);
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if (likely(mm == swap_token_mm)) {
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mm->swap_token_time = jiffies + SWAP_TOKEN_CHECK_INTERVAL;
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swap_token_mm = &init_mm;
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swap_token_check = jiffies;
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}
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